- Country: US
- State: IL
- Latitude: 41.856
- Longitude: -87.609
High Temperatures
On May 20 in NORTHERLY ISLAND the average high temperature is 71.4 °F (21.9 °C). The lowest recored high temperature was 52.0 °F (11.1 °C) in 2015 and the highest recored high temperature was 88.5 °F (31.4 °C) in 2013. The high temperature is usually* between 63.2 °F (17.4 °C) and 79.6 °F (26.4 °C). About a quarter of the time, the high temperature is less than 63.2 °F (17.4 °C), and another quarter of the time, the high temperature is greater than and 79.6 °F (26.4 °C). About 95% of the time, the high temperature has been between 47.7 °F (8.7 °C) and 95.2 °F (35.1 °C).
Low Temperatures
On May 20 in NORTHERLY ISLAND the average low temperature is 50.4 °F (10.2 °C). The lowest recored low temperature was 41.0 °F (5.0 °C) in 2015 and the lowest recored low temperature was 61.9 °F (16.6 °C) in 2013. The low temperature is usually* between 46.0 °F (7.8 °C) and 54.9 °F (12.7 °C). About a quarter of the time, the low temperature is less than 46.0 °F (7.8 °C), and another quarter of the time, the low temperature is greater than and 54.9 °F (12.7 °C). About 95% of the time, the low temperature has been between 37.5 °F (3.0 °C) and 63.4 °F (17.4 °C).
Frost
On May 20 in NORTHERLY ISLAND expect the temperatures to drop below freezing for a risk of frost about 0.3% 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