Station information
- Integrated Surface Dataset (ISD) station ID: 998499
- Country: US
- State: IL
- Latitude: 41.856
- Longitude: -87.609
High Temperatures
On July 30 in NORTHERLY ISLAND the average high temperature is 81.3 °F (27.4 °C). The lowest recored high temperature was 70.0 °F (21.1 °C) in 2014 and the highest recored high temperature was 91.0 °F (32.8 °C) in 2025. The high temperature is usually* between 76.9 °F (25.0 °C) and 85.6 °F (29.8 °C). About a quarter of the time, the high temperature is less than 76.9 °F (25.0 °C), and another quarter of the time, the high temperature is greater than and 85.6 °F (29.8 °C). About 95% of the time, the high temperature has been between 68.7 °F (20.4 °C) and 93.9 °F (34.4 °C).
Low Temperatures
On July 30 in NORTHERLY ISLAND the average low temperature is 68.6 °F (20.3 °C). The lowest recored low temperature was 63.1 °F (17.3 °C) in 2014 and the lowest recored low temperature was 74.8 °F (23.8 °C) in 2012. The low temperature is usually* between 66.1 °F (18.9 °C) and 71.1 °F (21.7 °C). About a quarter of the time, the low temperature is less than 66.1 °F (18.9 °C), and another quarter of the time, the low temperature is greater than and 71.1 °F (21.7 °C). About 95% of the time, the low temperature has been between 61.2 °F (16.2 °C) and 76.0 °F (24.4 °C).
Frost
On July 30 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