- Country: US
- State: IL
- Latitude: 41.856
- Longitude: -87.609
High Temperatures
On April 17 in NORTHERLY ISLAND the average high temperature is 59.1 °F (15.1 °C). The lowest recored high temperature was 37.2 °F (2.9 °C) in 2018 and the highest recored high temperature was 74.1 °F (23.4 °C) in 2019. The high temperature is usually* between 50.6 °F (10.3 °C) and 67.7 °F (19.8 °C). About a quarter of the time, the high temperature is less than 50.6 °F (10.3 °C), and another quarter of the time, the high temperature is greater than and 67.7 °F (19.8 °C). About 95% of the time, the high temperature has been between 34.3 °F (1.3 °C) and 84.0 °F (28.9 °C).
Low Temperatures
On April 17 in NORTHERLY ISLAND the average low temperature is 39.0 °F (3.9 °C). The lowest recored low temperature was 27.0 °F (-2.8 °C) in 2018 and the lowest recored low temperature was 46.9 °F (8.3 °C) in 2024. The low temperature is usually* between 34.7 °F (1.5 °C) and 43.4 °F (6.3 °C). About a quarter of the time, the low temperature is less than 34.7 °F (1.5 °C), and another quarter of the time, the low temperature is greater than and 43.4 °F (6.3 °C). About 95% of the time, the low temperature has been between 26.4 °F (-3.1 °C) and 51.7 °F (11.0 °C).
Frost
On April 17 in NORTHERLY ISLAND expect the temperatures to drop below freezing for a risk of frost about 13.8% 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 2013 to 2025