St. John's climate

St. John's Weather in September

NASA POWER reanalysis for the half-degree grid cell around St. John's, 1991-2020; a grid cell is an area average and can differ from a thermometer in town by several degrees

Average highs run from 16°C on September 1 to 13°C on September 30, and lows from 13°C to 9°C. Normal precipitation for the month is 104 mm over about 14 wet days.

September day by day

The normal high and low for each date, in °C.

Normal daily high and low temperature at St. John's, in °C, with the record for each date.510152025151015202530
  • Normal low
  • Normal high
  • Reanalysis extreme high
  • Reanalysis extreme low

September at a glance

Average high
15°C
Average low
11°C
Precipitation
104 mm
Reanalysis high
24°CSep 10, 2001
Reanalysis low
5°CSep 26, 2010
Daylight
13 h 22 min to 11 h 43 min
Cloud cover
71%
Humidity
87%
Dew point
11°C
Wind
21.2 km/h

Every day of the month

A wet day has at least 1 mm of precipitation in the reanalysis.

DateNormal highNormal lowReanalysis highReanalysis lowChance wet
Sep 116°C13°C20°C 20128°C 200248%
Sep 216°C13°C19°C 19998°C 199148%
Sep 316°C13°C21°C 19997°C 199148%
Sep 416°C12°C20°C 20058°C 199249%
Sep 516°C12°C20°C 20038°C 199250%
Sep 616°C12°C20°C 20118°C 199249%
Sep 716°C12°C19°C 20169°C 199247%
Sep 816°C12°C19°C 19998°C 201545%
Sep 916°C12°C21°C 20018°C 200945%
Sep 1015°C12°C24°C 20017°C 200946%
Sep 1115°C12°C20°C 20127°C 199147%
Sep 1215°C12°C19°C 19997°C 199146%
Sep 1315°C11°C19°C 20157°C 199147%
Sep 1415°C11°C21°C 20037°C 199148%
Sep 1515°C11°C21°C 20037°C 199146%
Sep 1615°C11°C20°C 20038°C 200945%
Sep 1715°C11°C20°C 20038°C 199546%
Sep 1814°C11°C18°C 19996°C 201844%
Sep 1914°C11°C17°C 19947°C 201944%
Sep 2014°C10°C18°C 20008°C 199544%
Sep 2114°C10°C18°C 20067°C 201845%
Sep 2214°C10°C18°C 20007°C 199146%
Sep 2314°C10°C17°C 20127°C 199148%
Sep 2414°C10°C18°C 20017°C 199648%
Sep 2513°C10°C18°C 20126°C 199649%
Sep 2613°C10°C17°C 20175°C 201048%
Sep 2713°C10°C17°C 20085°C 201548%
Sep 2813°C10°C17°C 20206°C 199748%
Sep 2913°C9°C18°C 20207°C 199548%
Sep 3013°C9°C19°C 20136°C 201749%

Chance of rain

The chance of at least 1 mm of precipitation in the reanalysis on each date at St. John's, in percent.010203040501102030
  • Chance of a wet day

Sunrise and sunset

Times for 2026, local time (GMT-2:30).

September 1
sunrise 6:19 AM, sunset 7:41 PM
September 30
sunrise 6:59 AM, sunset 6:42 PM

Every day of September: sun and moon

Other months

Sources

Cloud, humidity, wind and sunshine, and temperature and precipitation: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-26. Sun and moon: computed with the NOAA solar equations and Meeus.