A changeable, rather wet, month

Temperatures

The average maximum temperature during September 2017 in Shoreham was 18.8 Celsius (66F), and that was less than 1 Celsius (1.8F) above normal for the time of year. The average minimum temperature was 11.7 Celsius (53F), and that was  slightly below the normal September value.

The highest temperature recorded during the month was 21.9 Celsius (72F) on both the 1st and 26th, but there were 4 other days when the temperature rose above 20 Celsius (68F). On most days the temperature rose to between 17 and 20 Celsius (63-68F), with only 2 days having maxima below 17 Celsius (63F). These cooler days were the 19th and 30th with highs of 16.2 Celsius (61F) and 16.9 Celsius (63F) respectively..

There were few warm nights during September, and minima above 15 Celsius (59F) only occurred on 3 nights. The 4th/5th had a low of 16.8 Celsius (62F), The 7th/8th was also a warm night, and on  the 27th/28th a low of 15.6 Celsius (60F) was recorded. There were several fairly cool nights, these mainly occurring around the middle of the month. There was a total of 10 nights with minima below 10 Celsius, with 9 of these cooler nights occurring between the 10th and 22nd. Only 4 nights had  a minimum temperature below 9 Celsius (48F), with just the 17th dipping below 8 Celsius (46F). The minimum on the night of the 16th/17th was 7.2 Celsius (45F).

The sea temperature,  around 19 Celsius (66F) at the beginning of September fell to 16 or 17 Celsius (61-63F) after mid month.

Frost

There were no frosts in Shoreham during September. The lowest grass minimum was 3.3 Celsius (38F) on the 15th.

Rain

There were 63.8 millimetres (2.5 ins.) of rain during September, and that was over 25% above average. Rain fell on 20 days, about 9 days above what one would expect at this time of year, and wet days ( rainfall of 1 millimetre (0.04 ins) or more)  amounted to 13 days. No measurable rain fell on the first 2 days of the month, but 3 millimetres (0.1 ins.) fell on the 3rd,  and only twice more during the month were there 2 consecutive days without measurable rain. After another 3 millimetres (0.1 ins.) on the 7th, over 9 millimetres (0.35 ins.) of rain were recorded on the 8th. Amounts of rain were generally small between  the 9th and 26th, although on 3 occasions, the 12th, 18th and 24th, rainfall totalled between 3 and 4 millimetres (about 0.1 ins.). The 27th was particularly wet in the evening and overnight with 17.8 millimetres (0.7 ins.) added to the monthly total. Over 4 millimetres (0.15 ins.) was logged for the 28th, with a further 5 millimetres (0.2 ins. ) falling on the last day of the month.

*A rain day is from 0900-0900 UTC

Hail

There was no hail reported  in Shoreham during September.

Thunder

There was no thunder reported in Shoreham during September.

Wind

September was another ‘westerly’ month with over two thirds of winds blowing from between southwest and northwest. The first half of September was often quite breezy but it became generally less windy after mid month. At Shoreham Airport  a gust of 44 knots (50 mph) was recorded early in the evening of the 10th, with 38 knots (43 mph) measured late morning on the following day. A further gust of 44 knots (50 mph) occurred  in the early hours of the 13th.

Fog

There was no fog observed in Shoreham during September.

Statistics for September 2017