Station information
- Integrated Surface Dataset (ISD) station ID: 998499
- Country: US
- State: IL
- Latitude: 41.856
- Longitude: -87.609
High Temperatures
On January 21 in NORTHERLY ISLAND the average high temperature is 31.9 °F (-0.0 °C). The lowest recored high temperature was 10.9 °F (-11.7 °C) in 2025 and the highest recored high temperature was 59.0 °F (15.0 °C) in 2017. The high temperature is usually* between 23.9 °F (-4.5 °C) and 39.9 °F (4.4 °C). About a quarter of the time, the high temperature is less than 23.9 °F (-4.5 °C), and another quarter of the time, the high temperature is greater than and 39.9 °F (4.4 °C). About 95% of the time, the high temperature has been between 8.7 °F (-12.9 °C) and 55.1 °F (12.9 °C).
Low Temperatures
On January 21 in NORTHERLY ISLAND the average low temperature is 16.4 °F (-8.7 °C). The lowest recored low temperature was -6.5 °F (-21.4 °C) in 2025 and the lowest recored low temperature was 35.1 °F (1.7 °C) in 2017. The low temperature is usually* between 7.8 °F (-13.4 °C) and 24.9 °F (-3.9 °C). About a quarter of the time, the low temperature is less than 7.8 °F (-13.4 °C), and another quarter of the time, the low temperature is greater than and 24.9 °F (-3.9 °C). About 95% of the time, the low temperature has been between -8.5 °F (-22.5 °C) and 41.2 °F (5.1 °C).
Frost
On January 21 in NORTHERLY ISLAND expect the temperatures to drop below freezing for a risk of frost about 89.1% 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