- Country: US
- State: IL
- Latitude: 41.856
- Longitude: -87.609
High Temperatures
On July 20 in NORTHERLY ISLAND the average high temperature is 83.7 °F (28.7 °C). The lowest recored high temperature was 75.4 °F (24.1 °C) in 2014 and the highest recored high temperature was 93.6 °F (34.2 °C) in 2019. The high temperature is usually* between 79.5 °F (26.4 °C) and 87.8 °F (31.0 °C). About a quarter of the time, the high temperature is less than 79.5 °F (26.4 °C), and another quarter of the time, the high temperature is greater than and 87.8 °F (31.0 °C). About 95% of the time, the high temperature has been between 71.7 °F (22.0 °C) and 95.6 °F (35.4 °C).
Low Temperatures
On July 20 in NORTHERLY ISLAND the average low temperature is 69.8 °F (21.0 °C). The lowest recored low temperature was 64.0 °F (17.8 °C) in 2024 and the lowest recored low temperature was 78.3 °F (25.7 °C) in 2022. The low temperature is usually* between 66.6 °F (19.2 °C) and 73.0 °F (22.8 °C). About a quarter of the time, the low temperature is less than 66.6 °F (19.2 °C), and another quarter of the time, the low temperature is greater than and 73.0 °F (22.8 °C). About 95% of the time, the low temperature has been between 60.4 °F (15.8 °C) and 79.2 °F (26.2 °C).
Frost
On July 20 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