Cortland, IL
Climate overview — based on NOAA 1991-2020 normals from DE KALB, IL US.
Year-round temperatures (°F)
Climate summary
Cortland has an annual average temperature of 48.5°F with about 37.3 inches of precipitation per year and 33.1 inches of snow. The warmest month is July (average high 83.1°F), and the coldest is January (average low 13.1°F). May is typically the wettest month (4.79 in) and January the driest (1.69 in). Snow typically falls from November through April.
Best time to visit Cortland
Full guide →Climate change signal
All-time records →58 of 366 (15.8%) of Cortland's all-time daily heat records have been set since 2015. If records were spread evenly across the station's history, only about 5% would fall in any given decade.
| 1960s | 17 | |
| 1970s | 63 | |
| 1980s | 67 | |
| 1990s | 56 | |
| 2000s | 61 | |
| 2010s | 71 | |
| 2020s | 31 |
Bars: number of all-time daily heat records still standing that were set in each decade.
Monthly averages
| Month | Avg High | Avg Low | Avg Temp | Precipitation | Snow | Rainy days |
|---|---|---|---|---|---|---|
| January | 28.1°F | 13.1°F | 20.6°F | 1.69 in | 10.2 in | 10 |
| February | 32.5°F | 16.6°F | 24.5°F | 1.71 in | 8.7 in | 8 |
| March | 45.0°F | 26.8°F | 35.9°F | 2.24 in | 4.4 in | 10 |
| April | 58.6°F | 37.3°F | 48.0°F | 3.56 in | 1.3 in | 12 |
| May | 70.2°F | 49.2°F | 59.7°F | 4.79 in | — | 13 |
| June | 79.9°F | 59.5°F | 69.7°F | 4.57 in | — | 11 |
| July | 83.1°F | 63.3°F | 73.2°F | 4.00 in | — | 10 |
| August | 81.2°F | 61.3°F | 71.3°F | 4.06 in | — | 9 |
| September | 74.9°F | 53.2°F | 64.0°F | 3.32 in | — | 9 |
| October | 62.0°F | 41.0°F | 51.5°F | 2.96 in | 0.1 in | 10 |
| November | 46.3°F | 29.6°F | 37.9°F | 2.31 in | 1.8 in | 9 |
| December | 33.6°F | 19.1°F | 26.3°F | 2.04 in | 6.6 in | 10 |
Climate twins of Cortland
Why these? →The most climatically similar US cities at least 140 miles away (by monthly temperature + precipitation pattern).