Station information
- Integrated Surface Dataset (ISD) station ID: 998499
- Country: US
- State: IL
- Latitude: 41.856
- Longitude: -87.609
High Temperatures
On July 12 in NORTHERLY ISLAND the average high temperature is 80.9 °F (27.2 °C). The lowest recored high temperature was 71.1 °F (21.7 °C) in 2021 and the highest recored high temperature was 89.1 °F (31.7 °C) in 2025. The high temperature is usually* between 76.5 °F (24.7 °C) and 85.3 °F (29.6 °C). About a quarter of the time, the high temperature is less than 76.5 °F (24.7 °C), and another quarter of the time, the high temperature is greater than and 85.3 °F (29.6 °C). About 95% of the time, the high temperature has been between 68.1 °F (20.1 °C) and 93.6 °F (34.2 °C).
Low Temperatures
On July 12 in NORTHERLY ISLAND the average low temperature is 68.0 °F (20.0 °C). The lowest recored low temperature was 63.7 °F (17.6 °C) in 2013 and the lowest recored low temperature was 83.8 °F (28.8 °C) in 2016. The low temperature is usually* between 65.1 °F (18.4 °C) and 71.0 °F (21.6 °C). About a quarter of the time, the low temperature is less than 65.1 °F (18.4 °C), and another quarter of the time, the low temperature is greater than and 71.0 °F (21.6 °C). About 95% of the time, the low temperature has been between 59.5 °F (15.3 °C) and 76.6 °F (24.8 °C).
Frost
On July 12 in NORTHERLY ISLAND 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:
- NORTHERLY ISLAND — Integrated Surface Dataset (ISD) station ID: 998499 — from year 2012 to 2025