Weather in southwest France: 2010 roundup

Every month I post an update on how the weather has been, based on the statistics we have kept since 1998. To see the other weather posts, please click on ‘Weather’ under the Topics tab in the right-hand sidebar.

It’s time for the end of year weather roundup. The Statistics Freak has been working hard crunching the numbers. I’ll give you the lowdown for December first, then I’ll analyse how the year as a whole compares with previous years.

1. Weather assessment for December:

A quick reminder of our subjective weather assessment: we assign each day a plus if it’s fine, a minus if it’s bad and a zero if it’s indifferent or we can’t decide. In December 2010, there were:

Pluses – 15
Zeros – 7
Minuses – 9

The graph shows the percentage of plus days each December for the past 12 years (the line is the trend). Despite the fact that it snowed on three separate occasions in December 2010 (including 20 cm and a 10-hour power cut on Christmas Eve), this was one of the better Decembers in terms of number of pluses. Only two others beat it.

2. Frost nights

It was cold, though. We had 16 frost nights; only three previous Decembers out of 11 (we started counting in 1999) had more – 2001, 2005 and 2009. On Boxing Day morning it was –12.5ºC, which we haven’t seen for a long time.

3. Rainfall

Our rainfall stats go back to August 2004. December’s rainfall was almost spot on the average, with 74mm compared with an average of 73.5mm. It rained on 11 days, compared with 10.9 (!) days on average.

Verdict on 2010 as a whole

Although there were some nice months (notably April and July) in 2010, it was one of the gloomiest years we have had. The overall number of pluses (i.e. nice days) was 167, compared with an average of 179; our data is complete for 11 years. 2010 shares this record with 2007, which was also a gloomy year.

We have complete rainfall data for six years. In 2010, total rainfall was 909.5mm (average 836.3mm) and it rained on 122 days, compared with an average of 114.5; so a bit wetter than normal.

Finally, here’s a French weather dicton predicting the summer weather. I don’t know where they all originate from; there appear to be thousands of dictons, sometimes contradicting each other. This one is for Epiphany (6th January): Beaucoup d’étoiles le jour des rois, sécheresse et chaleur pendant l’été (if you can see many stars on the day of the kings – Epiphany – the summer will be hot and dry). It’s forecast to rain that day…