On September 21st, the solstice and summer end.
Summer 2017 was very hot… exceptionally dry in some regions, wet in others… and sunlight was very irregular, starting off very well in June before declining.
In fact, the thermal surplus mainly stood out in June, with July and August remaining less than one degree above their normals.
A very hot summer, paradoxically with little sunshine and nearly normal sunlight.
Let’s read below some figures that bring us back to the reality of the facts.
Heat dominated for almost the entire month of June until July 15, and beyond this date in the southeast quarter where heatwave episodes continued in August, while the thermometer showed a significant drop in the rest of France.
In the end, summer 2017 ranks on the podium of the hottest summers since 1945 with a national average of 20.8 degrees, calculated over 170 stations, behind 20.9 degrees in 2015 and especially 22.2 degrees in 2003, which still stands out well ahead.
This summer was marked by an early heatwave in mid-June and heat records broken across many regions. Heatwave episodes continued in the first half of July, before retreating to the southeast between the end of July and August, while other regions returned to more or less seasonal temperatures.
Persisting since July 2016, drought has been easing off since May, a persistent trend throughout the three summer months at a national level, but with significant regional disparities.
Result: 146 mm for the three summer months compared to a thirty-year average of 153 mm, resulting in a 4.6% deficit. However, the drought severely affected the southeast regions where rain was virtually absent all summer, while the southwest and northern half saw normal to surplus precipitation.
Over the past 14 months, since the onset of the drought, the country has received 659 mm of rain compared to a normal of 868 mm, a 24% deficit, a remarkable value over such an extended period.
Unlike 2015 and 2016, summer 2017 was very stormy, particularly in August, marked by north-south thermal and humidity contrasts boosting storms.
Over the three summer months, the sun shone for 721 hours across France instead of the normal 735 hours, a small deficit mainly due to the very dark second half of July and the mixed month of August.
