Station information
- Integrated Surface Dataset (ISD) station ID: 998499
- Country: US
- State: IL
- Latitude: 41.856
- Longitude: -87.609
High Temperatures
On August 18 in NORTHERLY ISLAND the average high temperature is 80.5 °F (27.0 °C). The lowest recored high temperature was 71.8 °F (22.1 °C) in 2012 and the highest recored high temperature was 91.0 °F (32.8 °C) in 2015. The high temperature is usually* between 76.9 °F (24.9 °C) and 84.2 °F (29.0 °C). About a quarter of the time, the high temperature is less than 76.9 °F (24.9 °C), and another quarter of the time, the high temperature is greater than and 84.2 °F (29.0 °C). About 95% of the time, the high temperature has been between 70.0 °F (21.1 °C) and 91.1 °F (32.8 °C).
Low Temperatures
On August 18 in NORTHERLY ISLAND the average low temperature is 67.5 °F (19.7 °C). The lowest recored low temperature was 62.1 °F (16.7 °C) in 2012 and the lowest recored low temperature was 69.8 °F (21.0 °C) in 2020. The low temperature is usually* between 65.6 °F (18.7 °C) and 69.4 °F (20.8 °C). About a quarter of the time, the low temperature is less than 65.6 °F (18.7 °C), and another quarter of the time, the low temperature is greater than and 69.4 °F (20.8 °C). About 95% of the time, the low temperature has been between 62.0 °F (16.7 °C) and 73.1 °F (22.8 °C).
Frost
On August 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