- Country: US
- State: IL
- Latitude: 41.856
- Longitude: -87.609
High Temperatures
On March 18 in NORTHERLY ISLAND the average high temperature is 47.8 °F (8.8 °C). The lowest recored high temperature was 35.2 °F (1.8 °C) in 2013 and the highest recored high temperature was 70.7 °F (21.5 °C) in 2025. The high temperature is usually* between 40.9 °F (4.9 °C) and 54.7 °F (12.6 °C). About a quarter of the time, the high temperature is less than 40.9 °F (4.9 °C), and another quarter of the time, the high temperature is greater than and 54.7 °F (12.6 °C). About 95% of the time, the high temperature has been between 27.7 °F (-2.4 °C) and 67.9 °F (19.9 °C).
Low Temperatures
On March 18 in NORTHERLY ISLAND the average low temperature is 31.6 °F (-0.2 °C). The lowest recored low temperature was 13.8 °F (-10.1 °C) in 2023 and the lowest recored low temperature was 37.9 °F (3.3 °C) in 2022. The low temperature is usually* between 27.0 °F (-2.8 °C) and 36.2 °F (2.3 °C). About a quarter of the time, the low temperature is less than 27.0 °F (-2.8 °C), and another quarter of the time, the low temperature is greater than and 36.2 °F (2.3 °C). About 95% of the time, the low temperature has been between 18.2 °F (-7.7 °C) and 45.0 °F (7.2 °C).
Frost
On March 18 in NORTHERLY ISLAND expect the temperatures to drop below freezing for a risk of frost about 52.5% 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