Station information
- Integrated Surface Dataset (ISD) station ID: 998499
- Country: US
- State: IL
- Latitude: 41.856
- Longitude: -87.609
High Temperatures
On February 21 in NORTHERLY ISLAND the average high temperature is 42.5 °F (5.8 °C). The lowest recored high temperature was 26.6 °F (-3.0 °C) in 2015 and the highest recored high temperature was 64.4 °F (18.0 °C) in 2024. The high temperature is usually* between 33.9 °F (1.1 °C) and 51.1 °F (10.6 °C). About a quarter of the time, the high temperature is less than 33.9 °F (1.1 °C), and another quarter of the time, the high temperature is greater than and 51.1 °F (10.6 °C). About 95% of the time, the high temperature has been between 17.6 °F (-8.0 °C) and 67.5 °F (19.7 °C).
Low Temperatures
On February 21 in NORTHERLY ISLAND the average low temperature is 24.5 °F (-4.2 °C). The lowest recored low temperature was 1.0 °F (-17.2 °C) in 2015 and the lowest recored low temperature was 37.9 °F (3.3 °C) in 2017. The low temperature is usually* between 17.0 °F (-8.3 °C) and 32.0 °F (0.0 °C). About a quarter of the time, the low temperature is less than 17.0 °F (-8.3 °C), and another quarter of the time, the low temperature is greater than and 32.0 °F (0.0 °C). About 95% of the time, the low temperature has been between 2.7 °F (-16.3 °C) and 46.3 °F (7.9 °C).
Frost
On February 21 in NORTHERLY ISLAND expect the temperatures to drop below freezing for a risk of frost about 75.0% 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:
- NORTHERLY ISLAND — Integrated Surface Dataset (ISD) station ID: 998499 — from year 2013 to 2025