Station information
- Integrated Surface Dataset (ISD) station ID: 998499
- Country: US
- State: IL
- Latitude: 41.856
- Longitude: -87.609
High Temperatures
On July 18 in NORTHERLY ISLAND the average high temperature is 83.3 °F (28.5 °C). The lowest recored high temperature was 72.5 °F (22.5 °C) in 2014 and the highest recored high temperature was 94.1 °F (34.5 °C) in 2013. The high temperature is usually* between 78.1 °F (25.6 °C) and 88.5 °F (31.4 °C). About a quarter of the time, the high temperature is less than 78.1 °F (25.6 °C), and another quarter of the time, the high temperature is greater than and 88.5 °F (31.4 °C). About 95% of the time, the high temperature has been between 68.2 °F (20.1 °C) and 98.4 °F (36.9 °C).
Low Temperatures
On July 18 in NORTHERLY ISLAND the average low temperature is 68.9 °F (20.5 °C). The lowest recored low temperature was 63.0 °F (17.2 °C) in 2025 and the lowest recored low temperature was 81.1 °F (27.3 °C) in 2013. The low temperature is usually* between 65.1 °F (18.4 °C) and 72.8 °F (22.6 °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 72.8 °F (22.6 °C). About 95% of the time, the low temperature has been between 57.8 °F (14.3 °C) and 80.1 °F (26.7 °C).
Frost
On July 18 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