Climate of NW3

Much like the rest of London, NW3's climate is a function of its proximity to the European continent, positioning close to the North Atlantic and the North Sea, and to some extent the Urban Heat Island effect and London's rather northerly latitude. The direction of the wind and the air mass this brings is largely responsible for which of these sources most influences the day-to-day weather. With the prevailing wind being broadly south-westerly, bringing tropical maritime air, this gives London its climate of consistent rainfall throughout the year, relatively low sunshine total and few snow days, as well as a lack of extremes of temperature, those generally coming when the wind switches away from this direction - to the Arctic north or Polar north-east for cold, and to the Continental south or south east for heat.

Thunderstorms are not frequent, and generally comparatively weak compared to those of the near continent. The main weather hazards in NW3 are strong winds, dense fog, and the odd heat wave or icy cold snap. Although not subject to river flooding since we are home to inner London's highest point (Whitestone Pond, 134 m), we have also experienced occasional brief flash flooding, typically from localised slow-moving thunderstorms.

Long-term Climate Averages

These are estimates for the long-term average weather conditions, i.e. the climate, at NW3.
They were derived from data for the period 1991-2020 - the WMO standard reference period - from nearby official Met Office sites (Heathrow and Northolt) by comparing observed data for recent years and adjusting accordingly.

  Temperature / °C Rain / mm Wind
Speed
/ mph
Days Of Days Of Snow Wet
Hours
Sun Hrs
(% of max)
Min Max Mean Range Rainfall >1mm
Days
Air
Frost
Thun
der
Lying Falling
Jan3.0 7.8 5.4 4.8 59 11 5.2 6 0.4 2.5 5 67 69 (30)
Feb3.0 8.2 5.6 5.2 45 9 5.1 6 0.3 2.5 5 52 78 (31)
March4.3 10.9 7.6 6.6 39 10 5.2 3 0.6 0.4 4 53 113 (34)
April6.0 14.3 10.2 8.3 42 10 4.9 0.7 1 0.2 2 46 161 (43)
May9.0 17.8 13.4 8.8 46 9 4.7 0 2 0 0 40 189 (43)
June12.0 20.9 16.4 8.9 47 9 4.4 0 3 0 0 37 194 (43)
July14.2 23.0 18.6 8.8 46 8 4.3 0 2.5 0 0 34 195 (43)
Aug14.1 22.5 18.3 8.4 54 8 4.0 0 2.5 0 0 38 185 (45)
Sep11.5 19.1 15.3 7.6 50 9 3.9 0 2 0 0 41 147 (43)
Oct8.6 14.8 11.7 6.2 65 11 4.1 0.3 1 0 0 49 118 (40)
Nov5.5 10.7 8.1 5.2 67 10 4.6 2 0.4 0.3 1 63 84 (35)
Dec3.6 8.2 5.9 4.6 57 11 5.1 5 0.3 1 3 62 65 (30)
              
Winter3.2 8.1 5.6 4.9 161 31 5.1 17 1 6 13 181 212 (30)
Spring6.4 14.3 10.4 7.9 127 29 4.9 3.7 3.6 0.6 6 139 463 (40)
Summer13.4 22.1 17.8 8.7 147 25 4.2 0 8 0 0 109 574 (44)
Autumn8.5 14.9 11.7 6.3 182 30 4.2 2.3 3.4 0.3 1 153 349 (40)
              
Sum        617 115   23 16 6.9 20 582 1598 (40)
Annual7.9 14.9 11.4 7.0 51 9.6 4.6 1.9 1.3 0.6 1.7 48.5 133.2 (40)
              
Range11.2 15.2 13.2 4.3 28 3 1.3 6 2.7 2.5 5 33 130

A day-by-day progression of the temperature averages can be found here.

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