St. John's Temperatures: Averages by Month





The numbers here tell you how hot and cold the weather usually is in St. John's, Newfoundland during each month of the year.

The average high and low temperatures are listed below monthly and annually for the city, in both degrees Fahrenheit and Celsius.

Maximums and minimums are only part of the temperature picture. To fill in the rest, there's information on how many days a month get above or below a given temperature.

To find out how often it rises over 10 or 20 °C each month in St. John's, scroll down farther. There are also monthly and yearly counts of days with frost and cold weather.

The first set of high and low temperatures are averages for 2010 to 2019. Everything else here is based on 1981 to 2010 weather.

10-year temperature averages for St. John's, 2010 to 2019
High °F Low °F   High °C Low °C
33 21 January 1 -6
31 19 February -1 -7
34 22 March 1 -6
43 28 April 6 -2
51 35 May 11 2
59 42 June 15 6
70 53 July 21 12
69 55 August 21 13
63 48 September 17 9
53 40 October 12 4
44 32 November 7 0
35 25 December 2 -4
49 35 Year 9 1
30-year temperature averages for St. John's, 1981 to 2010
High °F Low °F   High °C Low °C
31 17 January -1 -8
30 16 February -1 -9
34 21 March 1 -6
42 29 April 6 -2
52 35 May 11 2
60 43 June 16 6
69 52 July 21 11
69 53 August 20 12
62 47 September 17 8
51 39 October 11 4
43 31 November 6 0
35 24 December 2 -5
48 34 Year 9 1

Days of Hot Weather in St. John's

A hot day at St John's means highs in the twenties Celsius. About half of the summer days here get that warm. The thermometer can nudge above 30 °C (86 °F), but that doesn't happen often, only once or twice a decade.

Days per month in St. John's above 10 or 20 °C
  10 °C
50 °F
20 °C
68 °F
January 1 0
February 1 0
March 1 0
April 5 0
May 17 2
June 25 7
July 31 19
August 31 18
September 28 6
October 16 0
November 7 0
December 2 0
Year 165 53

When St. John's Has Frosty Weather

St. John's typically has 167 days a year when the minimum temperature is at 0 °C or below. The average date for the last frost in spring is May 30. Frost normally returns here on October 17. The frost-free period extends for 139 days on average between the final spring frost and the first fall frost.

Average number of days with freezing temperatures in St. John's
  0 °C
32 °F
January 30
February 27
March 29
April 23
May 9
June 1
July 0
August 0
September 0
October 4
November 16
December 26
Year 167

How Often St. John's Has Cold Temperatures

The chilliest winter nights at St. John's usually have lows between -10 and -20 °C (14 and -4 °F). Temperatures below -20 °C do happen, but not every year. Lows of less than -30 °C (-22 °F) are not normal here.

From November to May, it can remain below freezing here all day long. St. John's typically has 66 days a year when the temperature never rises above 0 °C.

Days per month on average in St. John's when the minimum temperature drops below -2 or -10 °C
  -2 °C
28 °F
-10 °C
14 °F
January 28 11
February 25 12
March 25 7
April 13 0
May 3 0
June 0 0
July 0 0
August 0 0
September 0 0
October 2 0
November 10 0
December 21 5
Year 126 35
References

Environment Canada. Meteorological Service of Canada. Canadian Climate Normals. 1981-2010 Climate Normals & Averages.

Jay Lawrimore, Ron Ray, Scott Applequist, Bryant Korzeniewski, Matthew Menne. 2016. Global Summary of the Month and Year, Version 1.0. NOAA National Centers for Environmental Information.

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