| 2023 Hardiness Zone: | Zone 6a: -10°F to -5°F Zone 5b: -15°F to -10°F | |
| 2012 Hardiness Zone: | Zone 5b: -15°F to -10°F | |
| 1990 Hardiness Zone: | Zone 5a: -20F to -15F | |
| Average First Frost Date: | Oct. 11 - Oct. 20 | |
| Average Last Frost Date: | Apr. 21 - Apr. 30 | |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers | |
| Ecoregion: | 54a - Illinois/Indiana Prairies | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 61356 - Princeton, IL | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 12 | 18 | 28 | 39 | 49 | 59 | 63 | 61 | 52 | 41 | 30 | 18 | 39 |
| Avg Max Temp (°F) | 29 | 35 | 48 | 61 | 73 | 82 | 85 | 83 | 77 | 64 | 48 | 35 | 60 |
| Avg Precip (In.) | 1.4 | 1.42 | 2.57 | 3.56 | 4.01 | 4.4 | 3.82 | 4.12 | 3.48 | 2.76 | 2.69 | 2.12 | 36.35 |