Last frost dates in Illinois
170 NOAA weather stations in Illinois have thirty years of frost records. The median station sees its last 32 °F night around Apr 18; across the state that ranges from Apr 2 to May 2, so pick the station nearest you rather than a state-wide figure.
| Plan sowing from this date | ||||||
|---|---|---|---|---|---|---|
| CAIRO 3N | Apr 2 | Apr 17 | Mar 19 | Oct 31 | 211 | Plan sowing from this date → |
| MT CARMEL | Apr 2 | Apr 17 | Mar 19 | Oct 31 | 209 | Plan sowing from this date → |
| BROWNSTOWN 4 SW | Apr 3 | Apr 25 | Mar 19 | Oct 24 | 202 | Plan sowing from this date → |
| GRAND CHAIN DAM 53 | Apr 3 | Apr 21 | Mar 17 | Nov 5 | 216 | Plan sowing from this date → |
| SMITHLAND L&D | Apr 3 | Apr 21 | Mar 18 | Oct 30 | 207 | Plan sowing from this date → |
| ALBION | Apr 4 | Apr 20 | Mar 20 | Oct 28 | 206 | Plan sowing from this date → |
| ALTON - MELVIN PRICE L&D | Apr 4 | Apr 19 | Mar 18 | Nov 5 | 214 | Plan sowing from this date → |
| BENTON 2 N | Apr 4 | Apr 21 | Mar 19 | Oct 28 | 206 | Plan sowing from this date → |
| REND LAKE DAM | Apr 4 | Apr 19 | Mar 21 | Oct 27 | 204 | Plan sowing from this date → |
| BROOKPORT DAM 52 | Apr 6 | Apr 23 | Mar 21 | Oct 27 | 203 | Plan sowing from this date → |
| CAHOKIA | Apr 6 | Apr 20 | Mar 22 | Oct 27 | 203 | Plan sowing from this date → |
| CARLYLE RSVR | Apr 6 | Apr 22 | Mar 23 | Oct 29 | 204 | Plan sowing from this date → |
| DU QUOIN 4 SE | Apr 6 | Apr 22 | Mar 23 | Oct 22 | 199 | Plan sowing from this date → |
| FAIRFIELD RADIO WFIW | Apr 7 | Apr 23 | Mar 23 | Oct 26 | 201 | Plan sowing from this date → |
| GRAYVILLE | Apr 7 | Apr 23 | Mar 24 | Oct 25 | 201 | Plan sowing from this date → |
| HARRISBURG | Apr 7 | Apr 25 | Mar 21 | Oct 26 | 202 | Plan sowing from this date → |
| NASHVILLE 1 E | Apr 7 | Apr 22 | Mar 24 | Oct 26 | 201 | Plan sowing from this date → |
| VIRDEN | Apr 7 | Apr 21 | Mar 22 | Oct 29 | 205 | Plan sowing from this date → |
| ANNA 2 NNE | Apr 8 | Apr 26 | Mar 22 | Oct 29 | 203 | Plan sowing from this date → |
| CAHOKIA ST LOUIS AP | Apr 8 | Apr 23 | Mar 23 | Oct 26 | 200 | Plan sowing from this date → |
| GLADSTONE DAM 18 | Apr 8 | Apr 23 | Mar 26 | Oct 29 | 202 | Plan sowing from this date → |
| KASKASKIA RVR NAVIGATION LOCK | Apr 8 | Apr 25 | Mar 22 | Oct 30 | 202 | Plan sowing from this date → |
| LAWRENCEVILLE INTL AP | Apr 8 | Apr 22 | Mar 26 | Oct 26 | 200 | Plan sowing from this date → |
| QUINCY DAM 21 | Apr 8 | Apr 23 | Mar 24 | Oct 30 | 204 | Plan sowing from this date → |
| CARBONDALE SEWAGE PLT | Apr 9 | Apr 25 | Mar 25 | Oct 22 | 195 | Plan sowing from this date → |
| CARBONDALE SOUTHERN IL AP | Apr 9 | Apr 25 | Mar 24 | Oct 22 | 195 | Plan sowing from this date → |
| FLORA | Apr 9 | Apr 23 | Mar 29 | Oct 24 | 198 | Plan sowing from this date → |
| IUKA 12 SW | Apr 9 | Apr 25 | Mar 27 | Oct 24 | 196 | Plan sowing from this date → |
| SALEM | Apr 9 | Apr 23 | Mar 25 | Oct 26 | 197 | Plan sowing from this date → |
| CHICAGO MIDWAY AP 3SW | Apr 10 | Apr 26 | Mar 30 | Nov 1 | 203 | Plan sowing from this date → |
| CHICAGO NORTHERLY IS | Apr 10 | Apr 25 | Mar 29 | Nov 5 | 208 | Plan sowing from this date → |
| FLORA 5 NW | Apr 10 | Apr 26 | Mar 26 | Oct 23 | 196 | Plan sowing from this date → |
| SHELBYVILLE DAM | Apr 10 | Apr 28 | Mar 30 | Oct 24 | 195 | Plan sowing from this date → |
| VANDALIA | Apr 10 | Apr 24 | Mar 28 | Oct 24 | 196 | Plan sowing from this date → |
| CHICAGO MIDWAY AP | Apr 11 | Apr 27 | Mar 30 | Oct 31 | 201 | Plan sowing from this date → |
| MATTOON | Apr 11 | Apr 28 | Mar 31 | Oct 29 | 199 | Plan sowing from this date → |
| MCLEANSBORO | Apr 11 | Apr 26 | Mar 27 | Oct 21 | 190 | Plan sowing from this date → |
| MT VERNON 3 NE | Apr 11 | Apr 26 | Mar 30 | Oct 22 | 193 | Plan sowing from this date → |
| BELLEVILLE SIU RSCH | Apr 12 | Apr 28 | Mar 28 | Oct 20 | 189 | Plan sowing from this date → |
| LAWRENCEVILLE 2WSW | Apr 12 | Apr 30 | Mar 31 | Oct 25 | 193 | Plan sowing from this date → |
| MORRISONVILLE | Apr 12 | Apr 27 | Mar 29 | Oct 20 | 190 | Plan sowing from this date → |
| PALESTINE | Apr 12 | Apr 26 | Mar 30 | Oct 22 | 193 | Plan sowing from this date → |
| SPARTA 1 W | Apr 12 | Apr 29 | Mar 29 | Oct 22 | 191 | Plan sowing from this date → |
| STREATOR 3 SE | Apr 12 | Apr 25 | Mar 30 | Oct 28 | 199 | Plan sowing from this date → |
| BENTLEY | Apr 13 | Apr 30 | Mar 30 | Oct 22 | 191 | Plan sowing from this date → |
| EFFINGHAM 3SW | Apr 13 | Apr 29 | Apr 1 | Oct 24 | 191 | Plan sowing from this date → |
| FULTON L&D #13 | Apr 13 | Apr 28 | Apr 1 | Oct 26 | 195 | Plan sowing from this date → |
| HILLSBORO | Apr 13 | Apr 28 | Mar 30 | Oct 24 | 192 | Plan sowing from this date → |
| NEWTON | Apr 13 | Apr 29 | Apr 1 | Oct 22 | 190 | Plan sowing from this date → |
| NEWTON 6 SSE | Apr 13 | Apr 27 | Mar 31 | Oct 22 | 191 | Plan sowing from this date → |
| PETERSBURG 1E | Apr 13 | Apr 28 | Mar 31 | Oct 21 | 189 | Plan sowing from this date → |
| ROBINSON | Apr 13 | Apr 28 | Apr 2 | Oct 22 | 190 | Plan sowing from this date → |
| WHITE HALL 1 E | Apr 13 | Apr 28 | Mar 30 | Oct 22 | 190 | Plan sowing from this date → |
| CARLINVILLE | Apr 14 | Apr 30 | Mar 31 | Oct 21 | 188 | Plan sowing from this date → |
| CASEY | Apr 14 | Apr 30 | Apr 2 | Oct 20 | 187 | Plan sowing from this date → |
| DECATUR WTP | Apr 14 | May 1 | Apr 1 | Oct 24 | 192 | Plan sowing from this date → |
| DIXON SPRINGS AGRIC CTR | Apr 14 | Apr 30 | Mar 28 | Oct 21 | 189 | Plan sowing from this date → |
| JERSEYVILLE 2 SW | Apr 14 | Apr 30 | Mar 31 | Oct 19 | 187 | Plan sowing from this date → |
| NEW BOSTON DAM 17 | Apr 14 | May 2 | Apr 1 | Oct 24 | 190 | Plan sowing from this date → |
| PITTSFIELD #2 | Apr 14 | Apr 30 | Mar 31 | Oct 21 | 189 | Plan sowing from this date → |
| QUINCY RGNL AP | Apr 14 | May 1 | Mar 30 | Oct 23 | 191 | Plan sowing from this date → |
| SPRINGFIELD CAPITAL AP | Apr 14 | Apr 29 | Apr 1 | Oct 20 | 187 | Plan sowing from this date → |
| CARMI 3 | Apr 15 | May 2 | Apr 2 | Oct 19 | 183 | Plan sowing from this date → |
| CHAMPAIGN 3S | Apr 15 | Apr 29 | Apr 1 | Oct 24 | 190 | Plan sowing from this date → |
| CHARLESTON | Apr 15 | May 3 | Apr 1 | Oct 23 | 187 | Plan sowing from this date → |
| MATTOON COLES CO AP | Apr 15 | Apr 30 | Apr 2 | Oct 24 | 189 | Plan sowing from this date → |
| OLNEY 2S | Apr 15 | May 3 | Apr 1 | Oct 23 | 189 | Plan sowing from this date → |
| RAMSEY | Apr 15 | May 1 | Apr 3 | Oct 19 | 185 | Plan sowing from this date → |
| SPRINGFIELD #2 | Apr 15 | Apr 30 | Apr 3 | Oct 22 | 188 | Plan sowing from this date → |
| SULLIVAN 3S | Apr 15 | Apr 30 | Apr 2 | Oct 22 | 187 | Plan sowing from this date → |
| TUSCOLA | Apr 15 | May 1 | Apr 3 | Oct 20 | 188 | Plan sowing from this date → |
| CHANNAHON DRESDEN ISL DAM | Apr 16 | May 3 | Apr 3 | Oct 26 | 191 | Plan sowing from this date → |
| CHICAGO OHARE INTL AP | Apr 16 | May 1 | Apr 3 | Oct 28 | 193 | Plan sowing from this date → |
| DECATUR AP | Apr 16 | Apr 30 | Apr 3 | Oct 22 | 187 | Plan sowing from this date → |
| NEOGA 4NW | Apr 16 | Apr 29 | Apr 3 | Oct 20 | 185 | Plan sowing from this date → |
| PEORIA GTR PEORIA AP | Apr 16 | May 4 | Apr 2 | Oct 23 | 189 | Plan sowing from this date → |
| PONTIAC | Apr 16 | May 2 | Apr 3 | Oct 24 | 191 | Plan sowing from this date → |
| RUSHVILLE | Apr 16 | May 3 | Apr 2 | Oct 23 | 189 | Plan sowing from this date → |
| WINDSOR | Apr 16 | Apr 30 | Apr 3 | Oct 22 | 187 | Plan sowing from this date → |
| HAVANA | Apr 17 | May 3 | Apr 2 | Oct 19 | 185 | Plan sowing from this date → |
| JACKSONVILLE 2 | Apr 17 | May 1 | Apr 3 | Oct 21 | 186 | Plan sowing from this date → |
| MASON CITY 4SE | Apr 17 | May 4 | Apr 4 | Oct 18 | 182 | Plan sowing from this date → |
| PANA | Apr 17 | May 3 | Apr 4 | Oct 23 | 188 | Plan sowing from this date → |
| PRAIRIE CITY 2S | Apr 17 | May 2 | Apr 4 | Oct 22 | 185 | Plan sowing from this date → |
| GOLDEN | Apr 18 | May 1 | Apr 3 | Oct 21 | 187 | Plan sowing from this date → |
| HENNEPIN | Apr 18 | May 3 | Apr 3 | Oct 22 | 188 | Plan sowing from this date → |
| ILLINOIS CITY DAM 16 | Apr 18 | May 2 | Apr 5 | Oct 24 | 188 | Plan sowing from this date → |
| PERRY 6 NW | Apr 18 | May 5 | Apr 4 | Oct 15 | 179 | Plan sowing from this date → |
| WINCHESTER | Apr 18 | May 5 | Apr 3 | Oct 20 | 183 | Plan sowing from this date → |
| ATHENS 4SW | Apr 19 | May 4 | Apr 6 | Oct 19 | 181 | Plan sowing from this date → |
| AURORA | Apr 19 | May 4 | Apr 5 | Oct 23 | 185 | Plan sowing from this date → |
| CHAMPAIGN WILLARD AP | Apr 19 | May 5 | Apr 6 | Oct 17 | 180 | Plan sowing from this date → |
| CHICAGO PALWAUKEE AP | Apr 19 | May 3 | Apr 4 | Oct 26 | 190 | Plan sowing from this date → |
| JACKSONVILLE 2E | Apr 19 | May 5 | Apr 5 | Oct 17 | 179 | Plan sowing from this date → |
| JOLIET BRANDON RD DAM | Apr 19 | May 7 | Apr 3 | Oct 25 | 188 | Plan sowing from this date → |
| KANKAKEE METRO WASTEWATER | Apr 19 | May 3 | Apr 5 | Oct 24 | 188 | Plan sowing from this date → |
| LITTLE RED SCHOOL HSE | Apr 19 | May 5 | Apr 6 | Oct 22 | 183 | Plan sowing from this date → |
| ROCK ISLAND L&D 15 | Apr 19 | May 4 | Apr 6 | Oct 22 | 184 | Plan sowing from this date → |
| ROSICLARE 5NW | Apr 19 | May 8 | Apr 3 | Oct 20 | 181 | Plan sowing from this date → |
| SIDELL 4N | Apr 19 | May 3 | Apr 4 | Oct 19 | 181 | Plan sowing from this date → |
| GALESBURG | Apr 20 | May 5 | Apr 6 | Oct 19 | 180 | Plan sowing from this date → |
| GENESEO | Apr 20 | May 6 | Apr 6 | Oct 20 | 180 | Plan sowing from this date → |
| LACON | Apr 20 | May 7 | Apr 5 | Oct 17 | 178 | Plan sowing from this date → |
| LINCOLN | Apr 20 | May 4 | Apr 5 | Oct 16 | 179 | Plan sowing from this date → |
| MORRIS 1 NW | Apr 20 | May 6 | Apr 6 | Oct 23 | 184 | Plan sowing from this date → |
| OGDEN | Apr 20 | May 7 | Apr 7 | Oct 21 | 182 | Plan sowing from this date → |
| OTTAWA 5SW | Apr 20 | May 5 | Apr 6 | Oct 22 | 183 | Plan sowing from this date → |
| ROMEOVILLE WFO | Apr 20 | May 6 | Apr 7 | Oct 22 | 184 | Plan sowing from this date → |
| BLOOMINGTON 5W | Apr 21 | May 5 | Apr 7 | Oct 20 | 181 | Plan sowing from this date → |
| CONGERVILLE 2NW | Apr 21 | May 7 | Apr 7 | Oct 17 | 178 | Plan sowing from this date → |
| DANVILLE | Apr 21 | May 7 | Apr 6 | Oct 20 | 181 | Plan sowing from this date → |
| DIXON 1W | Apr 21 | May 5 | Apr 7 | Oct 19 | 180 | Plan sowing from this date → |
| GIBSON CITY | Apr 21 | May 5 | Apr 10 | Oct 17 | 178 | Plan sowing from this date → |
| KNOXVILLE | Apr 21 | May 6 | Apr 7 | Oct 20 | 181 | Plan sowing from this date → |
| LA HARPE | Apr 21 | May 5 | Apr 6 | Oct 19 | 180 | Plan sowing from this date → |
| PARIS STP | Apr 21 | May 9 | Apr 6 | Oct 20 | 179 | Plan sowing from this date → |
| RANTOUL | Apr 21 | May 6 | Apr 7 | Oct 18 | 179 | Plan sowing from this date → |
| ALEDO | Apr 22 | May 6 | Apr 7 | Oct 19 | 181 | Plan sowing from this date → |
| AVON | Apr 22 | May 8 | Apr 7 | Oct 19 | 177 | Plan sowing from this date → |
| HOOPESTON | Apr 22 | May 8 | Apr 7 | Oct 19 | 180 | Plan sowing from this date → |
| MONMOUTH | Apr 22 | May 10 | Apr 9 | Oct 15 | 174 | Plan sowing from this date → |
| MONMOUTH 4NW | Apr 22 | May 7 | Apr 7 | Oct 14 | 174 | Plan sowing from this date → |
| PRINCETON | Apr 22 | May 7 | Apr 9 | Oct 17 | 177 | Plan sowing from this date → |
| PRINCEVILLE | Apr 22 | May 6 | Apr 8 | Oct 14 | 174 | Plan sowing from this date → |
| ANTIOCH | Apr 23 | May 9 | Apr 9 | Oct 21 | 179 | Plan sowing from this date → |
| CHAMPAIGN 9 SW | Apr 23 | May 9 | Apr 9 | Oct 13 | 170 | Plan sowing from this date → |
| CHENOA | Apr 23 | May 7 | Apr 9 | Oct 15 | 174 | Plan sowing from this date → |
| PARK FOREST | Apr 23 | May 11 | Apr 9 | Oct 20 | 179 | Plan sowing from this date → |
| PAXTON 2 WSW | Apr 23 | May 9 | Apr 9 | Oct 12 | 170 | Plan sowing from this date → |
| DE KALB | Apr 24 | May 10 | Apr 9 | Oct 18 | 177 | Plan sowing from this date → |
| HENNEPIN WTR TRMT PLT | Apr 24 | May 10 | Apr 11 | Oct 17 | 174 | Plan sowing from this date → |
| KEWANEE 1 E | Apr 24 | May 8 | Apr 10 | Oct 17 | 175 | Plan sowing from this date → |
| LAKE VILLA 2NE | Apr 24 | May 9 | Apr 11 | Oct 23 | 180 | Plan sowing from this date → |
| MOLINE QUAD CITY INTL AP | Apr 24 | May 9 | Apr 9 | Oct 18 | 176 | Plan sowing from this date → |
| PERU | Apr 24 | May 8 | Apr 11 | Oct 18 | 176 | Plan sowing from this date → |
| ROCKFORD GTR ROCKFORD AP | Apr 24 | May 8 | Apr 10 | Oct 17 | 174 | Plan sowing from this date → |
| WALNUT | Apr 24 | May 9 | Apr 10 | Oct 14 | 172 | Plan sowing from this date → |
| WATSEKA 2 NW | Apr 24 | May 10 | Apr 10 | Oct 16 | 174 | Plan sowing from this date → |
| BARRINGTON 3SW | Apr 25 | May 12 | Apr 10 | Oct 19 | 177 | Plan sowing from this date → |
| CRYSTAL LAKE 4NW | Apr 25 | May 9 | Apr 11 | Oct 22 | 179 | Plan sowing from this date → |
| NORMAL 4NE | Apr 25 | May 11 | Apr 11 | Oct 16 | 172 | Plan sowing from this date → |
| PIPER CITY | Apr 25 | May 10 | Apr 11 | Oct 20 | 175 | Plan sowing from this date → |
| WEST CHICAGO DUPAGE AP | Apr 25 | May 12 | Apr 11 | Oct 19 | 174 | Plan sowing from this date → |
| CHICAGO BOTANIC GARDEN | Apr 26 | May 11 | Apr 11 | Oct 21 | 176 | Plan sowing from this date → |
| ELGIN | Apr 26 | May 12 | Apr 12 | Oct 18 | 174 | Plan sowing from this date → |
| FREEPORT WASTE WTP | Apr 26 | May 11 | Apr 11 | Oct 13 | 169 | Plan sowing from this date → |
| GALENA | Apr 26 | May 11 | Apr 11 | Oct 15 | 170 | Plan sowing from this date → |
| GALVA | Apr 26 | May 11 | Apr 12 | Oct 12 | 166 | Plan sowing from this date → |
| MINONK | Apr 26 | May 10 | Apr 11 | Oct 17 | 173 | Plan sowing from this date → |
| MORRISON | Apr 26 | May 11 | Apr 13 | Oct 13 | 167 | Plan sowing from this date → |
| ROCHELLE | Apr 26 | May 12 | Apr 11 | Oct 13 | 168 | Plan sowing from this date → |
| COMPTON 1 NW | Apr 27 | May 14 | Apr 12 | Oct 12 | 167 | Plan sowing from this date → |
| DWIGHT | Apr 27 | May 14 | Apr 14 | Oct 15 | 170 | Plan sowing from this date → |
| MARSEILLES LOCK | Apr 27 | May 13 | Apr 12 | Oct 17 | 171 | Plan sowing from this date → |
| PAW PAW 2S | Apr 27 | May 12 | Apr 12 | Oct 15 | 171 | Plan sowing from this date → |
| STOCKTON 3 NNE | Apr 27 | May 12 | Apr 12 | Oct 9 | 165 | Plan sowing from this date → |
| WHEATON 3 SE | Apr 27 | May 14 | Apr 12 | Oct 17 | 173 | Plan sowing from this date → |
| ALTONA | Apr 28 | May 12 | Apr 15 | Oct 12 | 165 | Plan sowing from this date → |
| CHICAGO AURORA MUNI AP | Apr 28 | May 11 | Apr 14 | Oct 13 | 166 | Plan sowing from this date → |
| LISLE-MORTON ARBORETUM | Apr 28 | May 14 | Apr 14 | Oct 16 | 169 | Plan sowing from this date → |
| MARENGO | Apr 28 | May 14 | Apr 15 | Oct 12 | 166 | Plan sowing from this date → |
| SHABBONA 5 NNE | Apr 28 | May 13 | Apr 14 | Oct 10 | 163 | Plan sowing from this date → |
| MUNDELEIN 4 WSW | Apr 29 | May 15 | Apr 14 | Oct 20 | 172 | Plan sowing from this date → |
| POLO 5NW | Apr 29 | May 14 | Apr 15 | Oct 7 | 161 | Plan sowing from this date → |
| CHICAGO WAUKEGAN RGNL AP | Apr 30 | May 16 | Apr 14 | Oct 21 | 173 | Plan sowing from this date → |
| STREAMWOOD | Apr 30 | May 16 | Apr 17 | Oct 13 | 163 | Plan sowing from this date → |
| WAUKEGAN | Apr 30 | May 14 | Apr 15 | Oct 19 | 170 | Plan sowing from this date → |
| ELIZABETH | May 1 | May 17 | Apr 17 | Oct 9 | 160 | Plan sowing from this date → |
| MC HENRY -WG STRATTON L&D | May 1 | May 19 | Apr 16 | Oct 11 | 162 | Plan sowing from this date → |
| MT CARROLL | May 2 | May 18 | Apr 18 | Oct 7 | 154 | Plan sowing from this date → |
How to read the three dates
Average is the date by which, in half of the years between 1991 and 2020, the last 32 °F night had already happened. Safe is later: only one year in ten saw a frost after it, which is the date to transplant tomatoes and peppers, both killed by a single frost. Early is the risky end, with a frost after it in nine years out of ten.
Every figure is for the weather station, not for your garden. A valley bottom, a north slope or a spot near a lake can run a week or two either way. Cities are warmer than the countryside around them.
Where the numbers come from
The dates are NOAA's U.S. Climate Normals for 1991 to 2020, computed by the National Centers for Environmental Information for every station with thirty years of daily minimum temperatures. ZIP codes are matched to the nearest such station within 150 km using U.S. Census Bureau ZIP Code Tabulation Area centroids. Stations that never see a frost, such as much of south Florida, report no date and are left out.