- Country: US
- State: IL
- Latitude: 41.856
- Longitude: -87.609
High Temperatures
On May 18 in NORTHERLY ISLAND the average high temperature is 71.0 °F (21.7 °C). The lowest recored high temperature was 57.9 °F (14.4 °C) in 2016 and the highest recored high temperature was 83.5 °F (28.6 °C) in 2024. The high temperature is usually* between 65.0 °F (18.3 °C) and 77.0 °F (25.0 °C). About a quarter of the time, the high temperature is less than 65.0 °F (18.3 °C), and another quarter of the time, the high temperature is greater than and 77.0 °F (25.0 °C). About 95% of the time, the high temperature has been between 53.5 °F (11.9 °C) and 88.5 °F (31.4 °C).
Low Temperatures
On May 18 in NORTHERLY ISLAND the average low temperature is 51.0 °F (10.6 °C). The lowest recored low temperature was 43.0 °F (6.1 °C) in 2019 and the lowest recored low temperature was 64.0 °F (17.8 °C) in 2017. The low temperature is usually* between 47.0 °F (8.3 °C) and 55.1 °F (12.8 °C). About a quarter of the time, the low temperature is less than 47.0 °F (8.3 °C), and another quarter of the time, the low temperature is greater than and 55.1 °F (12.8 °C). About 95% of the time, the low temperature has been between 39.2 °F (4.0 °C) and 62.9 °F (17.2 °C).
Frost
On May 18 in NORTHERLY ISLAND expect the temperatures to drop below freezing for a risk of frost about 0.1% 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