Typical April brings big swings in air temperature

The old saying is “April showers bring May flowers”. Or as Chaucer (In Neville Coghill’s version) has it:

When in April the sweet showers fall

And pierce the drought of March to the root, and all

And veins are bathed in liquor of such power

As brings about the engendering of the flower

With just above average rainfall and sunshine in April, we would hope to have a good chance of a decent floral display this May. However, as well as somewhat typical amounts of rain and sun, there was also a quite typical variability in the weather.

Sunshine hours through April were on the average side, at 171.7 hours, just 7% above the long-term average (that’s over 30 years) of 160.6 hours. But of the 45.6 mm of rain that fell at our Invergowrie site through April (the most rain for an April month since 2016, when 64.8mm of rainfall was recorded), 38% of it (or 17.5 mm) fell on one day, April 11.

Furthermore, while mean air temperature was only slightly lower than the long-term average, at 7.8ºC (compared with the 8ºC long-term average), it saw a swing from 15.8ºC on April 21 to a low of -0.4 ºC, just four days later, on April 25.

1. Air Mean Temperature      Daily Air Mean = 7.8ºC

                        Lta Air Mean   =8.0ºC

                        Difference       =0.2ºC

Highest Air Temperature = 15.8ºC on date: 21/04/2023

Lowest Air Temperature = -0.4ºC on date: 25/04/2023

2. Rainfall       Total Rainfall  =45.6 mm

                        Lta Rainfall      =44.8 mm

                        Actual               = 101.8% of LTA

Highest daily rainfall       =17.5mm on date:11/04/2023       

3. Sunshine     Total Sunshine           = 171.7 hrs

                        Lta Sunshine    =160.6 hrs

                        Actual               =107% of LTA

* Note: LTA = Long Term Average (30 YEAR LONG TERM AVERAGE 1991-2020)

Please account for the fact this 30-year average is missing maximum air temperature readings between September-December 2017 due to The Met office removal of all mercury thermometers.

Disclaimer: The views expressed in this blog post are the views of the author(s), and not an official position of the institute or funder.