Wet at first, then Very Dry
Temperatures
The average maximum temperature during May 2023 in Shoreham was 18.6 Celsius (66F), and that was very slightly above normal for the time of year. The average minimum temperature was 9.2 Celsius (49F), which was close to average for May.
The highest temperature recorded during the month was 22.8 Celsius (73F) on the 28th, but maxima exceeded 20 Celsius (68F) on 5 other days, with all of these warmer days occurring after the 19th. Highs included 21.5 Celsius (71F) on the 22nd, and 22.1 Celsius (72F) on the 27th. On most days (19) the top temperature was in the range 17 to 20 Celsius (63-68F), but there were some cooler days before mid-month. On 6 days the temperature failed to rise above 17 Celsius (63F), but only 2 of the days had maxima below 15 Celsius (59F). On the 8th, a high of 14.7 Celsius (59F) occurred, but the coolest day of the month was the 6th, when the high was only 13.1 Celsius (56F).
There were no especially mild nights during May, although minima were above 10 Celsius (50F) on 8 nights. A total of 6 of these milder nights occurred before mid-month, with 5 of these having minima above 11 Celsius (52F). A low of 11.4 Celsius (53F) occurred on the 15th, but the mildest night of the month was the 9th with a low of 12.2 Celsius (54F). Other nights had lows ranging from 7 to 10 Celsius (45-50F), but there were 2 exceptions. On the 16th, a minimum of 6.2 Celsius (43F) occurred, but the 3rd was the coolest night of the month with a minimum of 6.0 Celsius (43F).
The sea temperature was 12 Celsius (54F) at the beginning of May, rising to 14 or 15 Celsius (57-59F) at the end of the month.
Frost
There were no air or grass frosts during May. The lowest grass temperature was 2.2 Celsius (36F) on the 3rd.
Rain
Rainfall in May amounted to 35.0 millimetres (1.4 ins.), which was around 10% below the monthly average. Measurable rain fell on only 6 days, which was 5 days below the average, and wet days (when 1 millimetre (0.04 ins.), or more, of rain falls) numbered 4, which was 4 days below the average. Showers on the 1st produced 0.8 millimetres (0.03 ins.), but the following 2 days were dry. The 7th was also dry, but the period between the 4th and 8th gave the only spell of unsettled weather during the month. During these 5 days there were 33.6 millimetres (1.3 ins.) of rain, with the vast bulk (86%) occurring on just 2 days. On the 6th, 13.6 millimetres (0.5 ins.) of rain was measured, with 16.6 millimetres (0.65 ins.) occurring on the 8th. During the remainder of the month there was only 1 more day with measurable rain. That day was the 12th, when 0.6 millimetres (0.02 ins.) was recorded.
Hail
No hail was observed in this part of Shoreham.
Thunder
No thunder was heard in this part of Shoreham.
Snow
There was no sleet or snow observed in this part of Shoreham.
Wind
Pressure during May was higher than average, with the centre of the anticyclones mostly positioned over, or to the west, of the UK. As a result, the usual pattern of southwesterly winds was largely reversed. Winds from the southwesterly quadrant occurred on only 4 days, whereas winds from between northwest and northeast were observed on 14 days, with the second half of May having winds from between north and east dominating. These latter winds were often quite brisk through both the day and the night, otherwise, there were no particularly strong winds during the month. At Shoreham Airport, the only gust above 30 knots (34 mph) during May occurred during the last hour of the month. Later in the evening of the 31st a northeasterly gust of 32 knots (36 mph) was recorded.
Fog
There was sea fog for a while early in the evening on the 14th.
Statistics for May 2023
| Reporting Site | Highest Temp | Lowest Temp | Rain Total (mm) | Wettest | Rain days |
| Shoreham A/P | 21.7 | 4.1 | 39 | 21 | 7 |
| Thorney Island | 22.5 | 6.4 | 37 | 16 | 6 |
| Gatwick A/P | 21.7 | 3.4 | 49 | 24 | 6 |
| Herstmonceux | 21.8 | 3.9 | 26 | 12 | 5 |
| Bournemouth (Hurn) | 24.1 | 2.9 | 62 | 16 | 9 |
| Middle Wallop | 22.5 | 4.1 | 45 | 13 | 8 |
| Dieppe | 23.2 | 4.9 | 13 | 11 | 5 |