- Country: US
- State: IL
- Latitude: 41.856
- Longitude: -87.609
High Temperatures
On September 15 in NORTHERLY ISLAND the average high temperature is 75.8 °F (24.3 °C). The lowest recored high temperature was 63.9 °F (17.7 °C) in 2014 and the highest recored high temperature was 84.9 °F (29.4 °C) in 2021. The high temperature is usually* between 71.3 °F (21.8 °C) and 80.3 °F (26.8 °C). About a quarter of the time, the high temperature is less than 71.3 °F (21.8 °C), and another quarter of the time, the high temperature is greater than and 80.3 °F (26.8 °C). About 95% of the time, the high temperature has been between 62.7 °F (17.1 °C) and 88.9 °F (31.6 °C).
Low Temperatures
On September 15 in NORTHERLY ISLAND the average low temperature is 60.6 °F (15.9 °C). The lowest recored low temperature was 55.9 °F (13.3 °C) in 2014 and the lowest recored low temperature was 68.9 °F (20.5 °C) in 2024. The low temperature is usually* between 57.4 °F (14.1 °C) and 63.8 °F (17.6 °C). About a quarter of the time, the low temperature is less than 57.4 °F (14.1 °C), and another quarter of the time, the low temperature is greater than and 63.8 °F (17.6 °C). About 95% of the time, the low temperature has been between 51.3 °F (10.7 °C) and 69.8 °F (21.0 °C).
Frost
On September 15 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 2024