The prevailing wind is from the South West. This is an area of high rainfall (over 1,800 mm/year) with a 'micro-climate' determined by its position between mountains.

Current weather data is available for the upper Senni Valley, 1 mile south of Heol Senni, from a Davis 'Vantage Vue' weather station which is maintained by the Webmaster.

Graphs of the weather in Senni are also available for the previous week, the previous month, and the previous year.

The annual rainfall here is about 2,102 mm, making it one of the wettest parts of the U.K.

The wettest month was January 2014, 477.6 mm of rain was recorded at this Weather Station. In the same period in 2013 there was 204.4 mm and in 2012 there was 160.8 mm. 477.6 mm is the largest monthly total of rain I have recorded for any month since I started doing this in 2012. In addition, 432.7 mm rain fell in December 2013 and 476.5mm rain fell in February 2014. So, in the three month period between 1/12/2013 - 28/02/2014, 1,386.8mm rain fell here. This is about 64% of the mean annual rainfall. 3.75" rain fell in 12 hours on 20/09/2018, the heaviest rainstorm many people here can recall.

The driest month was April 2017, with 27.3 mm of rain, only 25% of the average for April. April 2015, October 2016 and June 2018 were also dry months.

The hottest day was 25 July 2019: 28.9°C at 14:49. (It was nearly as hot two days before that). On the same day, it was 38.7°C in Cambridge, which was the hottest day ever recorded in the UK. A year earlier, on 26/07/2018 I recorded 27.3°C here.

Summary of monthly rainfall up to 31/07/2019, (mm rain): (10 days of data for July 2016 is missing)

See also Weather forecasts & the current Senni river level at Pont Hen Hafod, half way between Heol Senni and Defynnog

Flood_Dan_y_Graig_uchaf.jpg Mist_at_dawn.jpg Rainbow.jpg

Updated 28/02/2019