Stephenson County, IL
: September 2026 so far averaged 67°F in Stephenson County, IL, the warmest 1 to 29 September in the county average since 2019, 6th warmest of 76 (county average from NOAA gridded data, 1951 to 2026).
Last updated . This page normally updates every day; the latest update is late.
- High
- 77.2°F
- Warmest since 2025
- 14th warmest of 76
- Low
- 48.3°F
- Warmest since 2025
- 31st warmest of 76
No measurable precipitation in the county average of Stephenson County, IL for 4 days to Tuesday 29 September 2026 (county average from NOAA gridded data, 1951 to 2026).
- Normal range, 56.8 to 79.8°F
Every year as a table
Every 29 September low of the county average in Stephenson County, IL since 1951: 48.3°F in 2026; the lowest is 28°F, in 1984.
| Year | High, °F | Low, °F |
|---|---|---|
| 2026 | 77.2 | 48.3 |
| 2025 | 84.4 | 52.6 |
| 2024 | 79.4 | 56.2 |
| 2023 | 70.4 | 53.5 |
| 2022 | 59.9 | 35.2 |
| 2021 | 81.2 | 50.7 |
| 2020 | 61.3 | 42.3 |
| 2019 | 63.8 | 53.2 |
| 2018 | 55.8 | 35.5 |
| 2017 | 72.7 | 43 |
| 2016 | 62.3 | 49.7 |
| 2015 | 80.2 | 57.7 |
| 2014 | 81.9 | 52 |
| 2013 | 81.2 | 47.2 |
| 2012 | 71.1 | 37.8 |
| 2011 | 69.9 | 46.3 |
| 2010 | 72.6 | 45.1 |
| 2009 | 60 | 44.6 |
| 2008 | 66.5 | 51.5 |
| 2007 | 76.6 | 46.2 |
| 2006 | 58.2 | 39.9 |
| 2005 | 65.8 | 38.2 |
| 2004 | 66.3 | 37.7 |
| 2003 | 56.2 | 34.8 |
| 2002 | 79.4 | 51 |
| 2001 | 61.1 | 42.5 |
| 2000 | 70.5 | 43.5 |
| 1999 | 56.1 | 44.2 |
| 1998 | 77.1 | 51 |
| 1997 | 73 | 51.7 |
| 1996 | 63.5 | 47.7 |
| 1995 | 79.7 | 49.9 |
| 1994 | 64.1 | 40.2 |
| 1993 | 57 | 38.2 |
| 1992 | 56.9 | 32 |
| 1991 | 65.5 | 35 |
| 1990 | 66.3 | 45.7 |
| 1989 | 72.9 | 40.5 |
| 1988 | 68.2 | 53.7 |
| 1987 | 75.3 | 50.1 |
| 1986 | 77.1 | 62.2 |
| 1985 | 72.7 | 48.4 |
| 1984 | 53.2 | 28 |
| 1983 | 81.8 | 53 |
| 1982 | 76.2 | 51.6 |
| 1981 | 62.6 | 38.6 |
| 1980 | 63.3 | 44.8 |
| 1979 | 79.5 | 51.2 |
| 1978 | 68.1 | 42.2 |
| 1977 | 69.6 | 48.4 |
| 1976 | 64.2 | 42.3 |
| 1975 | 67.4 | 43.8 |
| 1974 | 67.1 | 42 |
| 1973 | 67.5 | 58.7 |
| 1972 | 66.5 | 39.4 |
| 1971 | 82.6 | 53.5 |
| 1970 | 68.8 | 36.9 |
| 1969 | 67.9 | 43.6 |
| 1968 | 66.4 | 46.7 |
| 1967 | 52.1 | 30.4 |
| 1966 | 62.4 | 49.5 |
| 1965 | 73.1 | 52.9 |
| 1964 | 65.5 | 34.2 |
| 1963 | 64.4 | 41.8 |
| 1962 | 63.5 | 33.1 |
| 1961 | 58.9 | 33.5 |
| 1960 | 63.8 | 46.9 |
| 1959 | 63.1 | 44.6 |
| 1958 | 67.2 | 41.8 |
| 1957 | 67.3 | 31.6 |
| 1956 | 73 | 53.3 |
| 1955 | 70.8 | 51.6 |
| 1954 | 76.3 | 59.4 |
| 1953 | 90.3 | 55.1 |
| 1952 | 79.1 | 49.5 |
| 1951 | 57.3 | 30.8 |
The month
August 2026 averaged 70.5°F in Stephenson County, IL, the warmest August in the county average since 2024, tied 57th warmest of 132 (with 2014) (county average from NOAA's monthly county data, 1895 to 2026).
The month in words
- Tuesday 29 September 2026: a high of 77.2°F averaged over Stephenson County, IL, the warmest 29 September in the county average since 2025, 14th warmest of 76 (county average from NOAA gridded data, 1951 to 2026).
- Tuesday 29 September 2026: a low of 48.3°F averaged over Stephenson County, IL, the warmest 29 September night in the county average since 2025, 31st warmest of 76 (county average from NOAA gridded data, 1951 to 2026).
- Days of the month without a value
- 0
Nearby
Rockford, IL 31.2 mi, the nearest city with its own station