- Country: US
- State: IL
- Latitude: 42.067
- Longitude: -87.683
High Temperatures
On September 15 in WILMETTE (CGS) the average high temperature is 68.2 °F (20.1 °C). The lowest recored high temperature was 64.9 °F (18.3 °C) in 1989 and the highest recored high temperature was 70.9 °F (21.6 °C) in 1987. The high temperature is usually* between 65.5 °F (18.6 °C) and 70.9 °F (21.6 °C). About a quarter of the time, the high temperature is less than 65.5 °F (18.6 °C), and another quarter of the time, the high temperature is greater than and 70.9 °F (21.6 °C). About 95% of the time, the high temperature has been between 60.4 °F (15.8 °C) and 76.0 °F (24.4 °C).
Low Temperatures
On September 15 in WILMETTE (CGS) the average low temperature is 58.7 °F (14.8 °C). The lowest recored low temperature was 56.8 °F (13.8 °C) in 1990 and the lowest recored low temperature was 64.9 °F (18.3 °C) in 1987. The low temperature is usually* between 55.0 °F (12.8 °C) and 62.4 °F (16.9 °C). About a quarter of the time, the low temperature is less than 55.0 °F (12.8 °C), and another quarter of the time, the low temperature is greater than and 62.4 °F (16.9 °C). About 95% of the time, the low temperature has been between 48.0 °F (8.9 °C) and 69.4 °F (20.8 °C).
Frost
On September 15 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