- Country: US
- State: IL
- Latitude: 42.067
- Longitude: -87.683
High Temperatures
On September 21 in WILMETTE (CGS) the average high temperature is 66.8 °F (19.3 °C). The lowest recored high temperature was 58.8 °F (14.9 °C) in 1987 and the highest recored high temperature was 68.9 °F (20.5 °C) in 1989. The high temperature is usually* between 63.0 °F (17.2 °C) and 70.6 °F (21.4 °C). About a quarter of the time, the high temperature is less than 63.0 °F (17.2 °C), and another quarter of the time, the high temperature is greater than and 70.6 °F (21.4 °C). About 95% of the time, the high temperature has been between 55.9 °F (13.3 °C) and 77.8 °F (25.4 °C).
Low Temperatures
On September 21 in WILMETTE (CGS) the average low temperature is 54.0 °F (12.2 °C). The lowest recored low temperature was 45.9 °F (7.7 °C) in 1990 and the lowest recored low temperature was 58.8 °F (14.9 °C) in 1989. The low temperature is usually* between 49.6 °F (9.8 °C) and 58.3 °F (14.6 °C). About a quarter of the time, the low temperature is less than 49.6 °F (9.8 °C), and another quarter of the time, the low temperature is greater than and 58.3 °F (14.6 °C). About 95% of the time, the low temperature has been between 41.4 °F (5.2 °C) and 66.6 °F (19.2 °C).
Frost
On September 21 in WILMETTE (CGS) expect the temperatures to drop below freezing for a risk of frost about 0.0% of the time.
Data Source(s)
The data used to compute the average high/low temperatures for this location were taken from the following stations:
- WILMETTE (CGS) — Integrated Surface Dataset (ISD) station ID: 722417 — from year 1987 to 1990