Very Warm and Dry

Temperatures

The average maximum temperature during May 2018 in Shoreham was 20.1 Celsius (68F), and that was around 4 degrees Celsius (7F) above normal for the time of year. The average minimum temperature was 9,8 Celsius (50F), and that was  also about 0.5 degrees Celsius (<1F) above  the May normal. Overall, it appears to be the warmest May in  the area for 20 years.

The highest temperature recorded during the month was 27.6 Celsius (82F) on the 28th, but there were 3 other days when the temperature rose above 25 Celsius (77F), namely the 7th, 26th and 27th with highs of 26.9 Celsius (81F), 26.8 Celsius (81F) and 25.1 Celsius (77F) respectively. In  what was a truly summer month, the temperature exceeded 20 Celsius (68F) on a further 13 days. There were several cool days, but these occurred early in the month. Of the 8 days with maxima below 17 Celsius (63F), none were recorded after the 19th. There were just 2 days when the temperature failed to reach 15 Celsius (59F). On the 1st, a high of 13.3 Celsius (56F) was measured, with 13.6 Celsius (57F) logged on the 12th.

Many nights had clear skies and light winds, and this led to some quite chilly temperatures around dawn. However, there were several warm nights, especially during the last week of May. On the 27th a minimum of 16.9 Celsius (63F) occurred, followed by 15.1 Celsius (59F) on the 29th. Overall, there were 14 nights with minimum temperatures above 10 Celsius (50F), with 9 of these milder nights occurring after the 21st. The coolest nights were at the beginning of May, and again just after mid month. There were 8 nights when the temperature dipped below 7 Celsius (45F), but only 2 of these cooler nights had minima below 5 Celsius (41F). The first night of the month had a low of 2.9 Celsius (37F), and the 18th had a minimum of 4.6 Celsius (40F). 

The sea temperature,  around  11  Celsius (52F) at the beginning of the month, steadily rose to 13 Celsius (55F) by the beginning of the second week, with a slower rise to 15 or 16  Celsius (60F) by the end of the month.

Frost

There were no air frosts during May, but a ground frost occurred on the first morning of the month, with the grass temperature falling to minus 1.1 Celsius (30F).   

Rain

There were 30.2 millimetres (1.2 ins.) of rain during May and that was only slightly more than 50% of the monthly average. It was the driest May in the area for 7 years. Rain fell on 11 days, about 1 day below what one would expect at this time of year, and wet days ( rainfall of 1 millimetre (0.04 ins) or more)  amounted to 8 days.  Rain was measured on the first 2 days* of May, but only totalled 5 millimetres (0.2 ins.). A dry spell of weather then ensued until the 23rd,  interrupted only twice by measurable rainfall. On the 9th, less than 1 millimetre (0.04 ins.) of rain fell, and on the 12th  over 7 millimetres (0.3 ins.) of rain was recorded.  The last 9 days of May were more changeable, and during this period the 27th was the only dry day.  Most daily totals were small, but over 4 millimetres (0.15 ins.) were recorded on the 24th, and 8.4 millimetres (0.33 ins.) on the 30th,  the wettest day of the month.    

*A rain day is from 0900-0900 UTC

Snow

No sleet or snow fell in Shoreham during May.

Hail

There was no hail observed in this part of Shoreham during May.

Thunder

There were 3 days with thunderstorms during May.  Distant thunder was heard early in the evening on the 21st, with distant lightning and thunder,  both to the east and west,  on the evening of the 26th.  The final thunderstorms were closer,  and  rumbled away from early to mid afternoon.

Wind

The winds during May were mainly from between southwest and northwest during the first 3 weeks, followed by breezes from between northeast and southeast during the remainder of the month.  Winds were generally gentle or moderate by day, falling light on many nights. There were exceptions, and at Shoreham Airport southwesterly gusts reached 32 knots (37 mph) on the afternoon of the 2nd, and late morning on the 16th there was a gust of 30 knots (34 mph) from the north,    

Fog

Mist and hill fog occurred on both the 20th and 30th, and misty low cloud descended to give fog for a while on the evening of the 31st.

Statistics for May 2018