Weather on May 20
Naperville, IL
55 Years of Data
Avg High
76°F
Avg Low
49°F
Warmest
1975
78°F avg
Coldest
2017
45°F avg
About This Date
May 20th in Naperville, IL typically brings pleasant spring weather, with average highs around 76°F and lows near 49°F — a 27°F daily swing. Over 55 years of records, the warmest May 20th was in 1975 (78°F average), while the coldest was 2017 (45°F) — a 33°F range across recorded history. Rain or other precipitation has occurred on about 33% of May 20th dates historically, with the wettest May 20th recording 3.51" of rain. The last decade has been 4.5°F cooler on this date compared to 20-30 years ago.
The last decade has been 4.5°F cooler on this date compared to 20-30 years ago.
Planning for May 20th in Naperville, IL? Great weather for outdoor activities. Consider bringing rain gear or an umbrella.
Cooling Trend
1.4°F per decade on this date
| Year | High | Low | Avg | Precip | Snow |
|---|---|---|---|---|---|
| 2025 | 54° | 41° | 47° | 0.97" | — |
| 2024 | 78° | 56° | 67° | — | — |
| 2023 | 73° | 41° | 57° | 0.18" | — |
| 2022 | 85° | 58° | 71° | — | — |
| 2021 | 75° | 63° | 69° | 0.41" | — |
| 2020 | 58° | 52° | 55° | 0.1" | — |
| 2019 | 74° | 46° | 60° | 0.23" | — |
| 2018 | 69° | 45° | 57° | — | — |
| 2017coldest | 48° | 42° | 45° | 1.12" | — |
| 2016 | 70° | 42° | 56° | — | — |
| 2015 | 56° | 38° | 47° | — | — |
| 2014 | 68° | 49° | 58° | — | — |
| 2013 | 87° | 65° | 76° | — | — |
| 2012 | 96° | 51° | 74° | — | — |
| 2011 | 73° | 49° | 61° | — | — |
| 2010 | 75° | 42° | 59° | — | — |
| 2009 | 79° | 46° | 62° | — | — |
| 2008 | 63° | 41° | 52° | 0.08" | — |
| 2007 | 80° | 48° | 64° | — | — |
| 2006 | 74° | 35° | 54° | — | — |
| 2005 | 74° | 50° | 62° | 0.41" | — |
| 2004 | 84° | 62° | 73° | — | — |
| 2003 | 74° | 53° | 63° | 0.56" | — |
| 2002 | 56° | 39° | 47° | 0.1" | — |
| 2001 | 80° | 47° | 63° | — | — |
| 2000 | 66° | 45° | 55° | — | — |
| 1999 | 82° | 46° | 64° | — | — |
| 1998 | 90° | 59° | 74° | — | — |
| 1997 | 68° | 37° | 53° | — | — |
| 1996 | 90° | 60° | 75° | 0.03" | — |
| 1995 | 77° | 54° | 65° | — | — |
| 1994 | 81° | 40° | 60° | — | — |
| 1993 | 63° | 37° | 50° | — | — |
| 1992 | 87° | 49° | 68° | — | — |
| 1991 | 79° | 48° | 63° | — | — |
| 1990 | 70° | 49° | 59° | 1.63" | — |
| 1989 | 76° | 59° | 67° | 3.51" | — |
| 1988 | 83° | 40° | 61° | — | — |
| 1987 | 84° | 54° | 69° | — | — |
| 1986 | 62° | 36° | 49° | — | — |
| 1985 | 79° | 60° | 69° | 0.71" | — |
| 1984 | 75° | 57° | 66° | 1.04" | — |
| 1983 | 70° | 54° | 62° | 0.2" | — |
| 1982 | 76° | 56° | 66° | 1.65" | — |
| 1981 | 78° | 32° | 55° | — | — |
| 1980 | 78° | 44° | 61° | — | — |
| 1979 | 80° | 46° | 63° | — | — |
| 1978 | 80° | 62° | 71° | — | — |
| 1977 | 91° | 58° | 74° | — | — |
| 1976 | 83° | 53° | 68° | — | — |
| 1975warmest | 92° | 65° | 78° | 0.36" | — |
| 1974 | 80° | 55° | 68° | — | — |
| 1973 | 74° | 39° | 56° | — | — |
| 1972 | 89° | 49° | 69° | — | — |
| 1971 | 69° | 46° | 58° | — | — |
55 years of data from LISLE - MORTON ARBORETUM