With 12.05 ° C average temperature
Over the past twelve months, the year 2020 stands out as the hottest year ever recorded in the Loire department since temperature readings were taken.
The previous record, which only dated from 2018, was set at 11.85 ° C. He himself had supplanted the record for 2003 (11.59 ° C), the summer of which was marked by an unprecedented heat wave. The three hottest years in the history of the Loire therefore correspond to the last two decades, and you need to know more about it.
+1 ° C on average compared to 2000
Is this observation enough to talk about global warming? “Not really,” says Christian David, a forecaster at the Météo France Interregional Meteorological Center in Lyon Bron. According to the specialist, it is preferable to observe the average temperatures for thirty years to observe longer-term changes.
Thus, during the period from 1991 to 2020, the average temperature in the Loire department was 10.78 ° C. This is higher than the previous period with an average temperature of 10.31 ° C between 1981 and 2010, and still above the average temperature of 9.87 ° C observed between 1971 and 2000. “The thirty-year averages are not increasing every decade,” says Christian David. “That is representative of climate change.”
The coldest day of the year in late December.
However, these changes do not prevent the balances from being respected in terms of seasonality: the coldest day of 2020 (in average temperature) was recorded on Saturday, December 26, with a minimum temperature of -1.8 ° C. in Saint- Etienne / Bouthéon and a maximum of -0.4 ° C.
As for the record for cold in Saint-Etienne, it was set on December 1: -6.8 ° C. On the contrary, the hottest day is Friday, July 31 with a minimum temperature of 20.4 ° C in Saint-Etienne / Bouthéon and a maximum of 38.8 ° C. As a reminder, the absolute record for heat in Saint-Etienne dates back to July 7, 2015: 41.1 ° C.
Also, the year 2020 was marked by fewer anomalies or extreme episodes. The Loire has only been put on a meteorological watch (orange level) on seven occasions in the last twelve months, compared to sixteen the previous year.
Météo France calculates an average temperature each day by counting the maximum temperature and the minimum temperature. The mean annual temperature is calculated on the basis of the aggregated daily averages from various high altitude or lowland stations.
No snow but cold on the weekend menu.
A risk of snow was forecast for next weekend in the Loire department. It seems finally removed, but the cold will be there. During the night from Friday to Saturday, the mercury should fluctuate between -2 ° C in the plains and down to -7 ° C in the relief of Pilat and the Forez mountains.
Starting under a heavy sky, Saturday will eventually see some clearings break in the afternoon but with a thermometer still cold: no more than 2 ° C in the hottest of the day in the most exposed sectors.
Same kind of Sunday weather: dry, a little brighter, but cold with a strong north / northwest wind. On the other hand, we will have to be attentive to a possible new degradation of the snow between Tuesday and next Wednesday. But the deadline is still too far away to be precise.
A greater gap in the Loire than in the rest of the country
Average temperatures observed in the Loire in 2020 exceed the previous record of +0.2 ° C: average temperature of 12.05 ° C in 2020 compared to 11.85 ° C in 2018.
Therefore, the hottest period of the year is more justified for the department.
If 2020 really sets a national record (average temperature 14 ° C), the 2018 record at the French level was only exceeded by 0.1 ° C (13.9 ° C in 2018).
The key values
557 millimeters of precipitation fell in 2020 in Saint-Etienne, significantly less than normal (718 millimeters). The amount of sun is, on the other hand, significantly higher than normal: 2,201 hours in total against 1,989 hours on average.