reef

Why on Earth are you using the 1981-2010 averages for 1991 then? Its standard to use the most recent 30 year average, so for 1991 that is 1961-1990.

Slightly warmer and wetter than average: 15.1C and 80mm

I imagine it'll be an east-west split month. We're still 1.2C below the 1981-2010 average here.

After a cool start it was a clear and sunny day throughout with small amounts of cirrus from late-afternoon on. Without an onshore breeze, it was the warmest day of the month so far. The air pressure was also notably high for May, reaching 1040.2hPa this morning - the highest I've ever recorded in May. Max Temp: 19.3C Min Temp: 4.9C Mean Wind: 10mph S Max Gust: 17mph Sunshine: 15.3hrs Rainfall: None Currently mostly clear with a temp of 12.3C.

After a cold and foggy start with a light ground frost it was a clear and sunny day throughout apart from some fair weather cloud around midday. Cooler than inland due to the easterly breeze but pleasant nonetheless. Max Temp: 14.3C Min Temp: 1.9C Mean Wind: 14mph E Max Gust: 19mph Sunshine: 13.1hrs Rainfall: None Currently mostly clear with a temp of 7.7C.

Every now and again you get a night like that. Oddly, the most notable one I can remember was 13th October last year where it didn't drop below 18.8C all night - not in summer, but it was so odd to be so warm overnight so late in the year.

Currently running at 7.1C (-3.1C) here to the 10th. A mean of 9.9C or less for the remainder of the month would see us record the coldest May on record. A long way to go, but something to keep an eye on.

Early sunny spells gave way to overcast conditions with light rain at times after midday, before brightening up once again in the evening. Rather cold again during the day after an overnight ground frost. Max Temp: 10.5C Min Temp: 0.5C Mean Wind: 11mph E Max Gust: 15mph Sunshine: 3.7hrs Rainfall: Trace Currently mostly cloudy with a temp of 6.7C.

After a sunny start with a ground frost it is now clouding over from the south. Currently 8.8C after a low of 0.5C.

Overcast with light rain or drizzle at times. Very cold again for the time of year, particularly so with the strength of the wind. Max Temp: 8.4C Min Temp: 6.7C Mean Wind: 17mph N Max Gust: 26mph Rainfall: 1.2mm Sunshine: None Currently overcast with a few clearances to the north and a temp of 6.7C.

Max / Min Temps here for the first week of May 1979: 1st: 6.9C / 1.3C 2nd: 8.1C / -1.6C 3rd: 7.1C / 1.1C 4th: 8.4C / -1.2C 5th: 9.5C / -0.1C 6th: 10.8C / 0.0C 7th: 11.6C / 4.7C Mean Max: 8.9C Mean Min: 0.6C Average: 4.8C (-4.7C) It soon changed though, it reached 24.5C on the 13th and 25.1C on the 14th! Its worth noting that if the GFS 06z were to come to fruition, we'd be on 8.0C to the 23rd and a mean of 11.6C or below for the remaining 8 days would see us record the coldest May on record. We're still a long way from that though.

We're currently on 7.4C (-2.8C) to the 8th. Other years with mean temps the same or lower to the 8th: 7.4C: 1991 7.4C: 1983 7.4C: 1980 6.4C: 1996 5.6C: 1979 If we stay sub-8C by the 11th (looking quite likely), then there's only 1979 and 1996 that are colder.

August has never been a reliably warm month. There have only in fact been 19 Augusts with a CET of above 17.5C back to 1659. It's never been a very sunny month either. I think perceptions are clouded by the unusual number of better than average Augusts in the 1990s and early 2000s.

8.8C to the 6th https://www.metoffice.gov.uk/hadobs/hadcet/cet_info_mean.html

Yes, confirmed as 9.1C: https://www.metoffice.gov.uk/hadobs/hadcet/mly_cet_mean_sort.txt

A few clearances overnight allowed the temperature to fall low enough for a ground frost, but during the daylight hours it has been almost totally cloudy. There was a light shower around midday and then further showers this evening. It was again rather cold. Max Temp: 8.9C Min Temp: 1.4C Mean Wind: 11mph NE Max Gust: 15mph Sunshine: 0.2hrs Rainfall: 0.4mm Currently overcast with light rain and a temp of 6.1C.

A day of heavy showers which were wintry at first this morning. It was exceptionally windy, with severe gusts during the heavier showers. These peaked at 83mph just before 10am and a further gust of 71mph during an afternoon shower. Both are comfortably the highest I've ever recorded and managed to blow down a nearby lamppost! Max Temp: 9.7C Min Temp: 0.8C Mean Wind: 32mph NNW Max Gust: 83mph (!) Sunshine: 7.7hrs Rainfall: 3.2mm Currently much calmer at 6.1C with a 10-15mph NW wind.

According to the wife we just had a gust of 83mph in that latest shower according to the Davis. Not sure I believe it!

Cold and partly cloudy overnight with a heavy ground frost and a min of 0.8C. We've then had a succession of heavy showers with rain, sleet and soft hail. The max was briefly 7.4C but now down to 4.7C in another passing shower.

After light rain overnight it was an overcast day with occasional moderate rain showers. A clearance came in the evening to give a short spell of late sunshine. The maximum temp of 8.3C was the lowest in May since 1997. Max Temp: 8.3C Min Temp: 3.6C Mean Wind: 17mph NW Max Gust: 20mph Sunshine: 0.4hrs Rainfall: 1.4mm Currently partly cloudy with a temp of 3.6C

I've never had a temperature sensor (SHT11/15 or 31) that has behaved that way. Generally when they fail they either read nothing or give massively wrong readings (usually on humidity rather than temperature mind you). Are the Davis and the screen located right next to each other? The SHT31 reacts extremely quickly in a FARS screen and can momentarily pick up large swings that the sensor/thermometer in the screen may not. I run two SHT31s - one in a DC-powered Davis FARS screen and another in a passive Davis 7717 screen as a backup and you do often get differences in sunny weather with wild temperature swings.

Where abouts in Yorkshire are you? Here 2018 was the warmest summer on record by some way, beating the previous warmest 2006 (itself marginally warmer than 1976) by a whole 0.4C. All three of the summer months were more than 1C above average, had 80% of average rainfall or less and 103% of average sunshine or more. We reached 30C for the first time in 17 years and 22 days surpassed 25C. Only 17 out of 92 days had rainfall >1mm and only 6 of those more than 5mm. It was truly an exceptional summer, perhaps about the best that is possible right now in this location. It remained warm well into Autumn aswell, with a maxima of 24.8C and min of 18.8C (!) as late as the 13th October.

It's gone from sunny to cloudy in the space of half an hour here but difficult to see if its convective as there's a lot of low level murk about.

Slightly milder and drier than average: 12.3C and 53mm

It must definitely be an east-west thing, because here last spring was very wet at 195.0mm, the second wettest since 2000. 2015 on the other hand was drier than average with 116.2mm compared to the average of 143.6mm.