Sunny and warm, then windy and wet 

Temperatures

The average maximum temperature during September 2019 in Shoreham was 19.9 Celsius (68F), and that was around 1.5 degrees Celsius (3F) above normal for the time of year. The average minimum temperature was 12.2 Celsius (54F), and that was very close to the September normal.    

The highest temperature recorded during the month was 23.3 Celsius (74F) on the 21st, but there were 13 other days when the temperature rose above 20 Celsius (68F), including 9 of the 11 days between the 10th and 20th. There were no particularly cool days during September, but maximum temperatures were below 20 Celsius (68F) from 5th to 9th inclusive, and from the 22nd until the end of the month. However, only 2 days had highs below 18 Celsius (64F). The 29th had a maximum of 17.8 Celsius (64F), but the coolest day of the month was the 9th when the temperature peaked at 16.3 Celsius (61F). 

There were a few fairly warm nights during September, these mainly occurring at either end of the month. On 2 occasions during the first week, and on 3 occasions during the last 9 days of September, the temperature stayed above 15 Celsius (59F), but only 1 of these days had a minimum above 17 Celsius (63F). That was on the 22nd when a low of 18.4 Celsius (65F) was recorded. There were several rather cool nights during the month, and temperatures dipped below 10 Celsius (50F) on 9 nights. However, there were only 2 of these cooler nights with minima below 8 Celsius (46F). On the 6th 7.3 Celsius  (45F) was measured, with 7.2 Celsius (45F) occurring on the 8th. 

The sea temperature was 19 or 20 Celsius (66-68F) at the beginning of September, but slowly fell to 17 Celsius (63F) by the end of the month.

Frost

There were neither air nor grass frosts during  September.  The lowest grass minimum temperature was 3.3 Celsius (38F) recorded on the 6th.    

Rain

There were  51.4  millimetres (2 ins.) of rain during September and that was very close to the monthly average. There were 15 days of measurable rain, and that was about 3 days above normal for September. Although the first 3 weeks of September were unsettled at times,  particularly during the second week, it was often sunny, especially during the afternoons, and more generally through the third week. Rain fell on just 7 days between the 1st and 22nd inclusive and the total for this period was a meagre 8.6 millimetres (0.3 ins.). The highest daily total was 4.6 millimetres (0.2 ins.) on the 3rd, with no rain measured between the 13th and 20th inclusive.  The end of the month became very unsettled with rain recorded on  each of the last 10 days of September.  Although much of the rain was light and drizzly,   some heavy bursts occurred, and on the 23rd a total of 16.2 millimetres (0.6 ins.) was measured. A further 6.2 millimetres (0.2 ins.) fell on the 24th, with over 10 millimetres (0.4 ins.) recorded on the 28th. 

Hail

No hail was observed in Shoreham during September.

Thunder

There was no thunder heard during September.

Snow

There was no sleet or snow observed in Shoreham during September.   

Wind

Although September was a westerly month, pressure was relatively high during the first 3 weeks, and winds were mainly gentle or moderate, although some brisk afternoon sea breezes occurred. During the third week, breezes were generally from the east or northeast, but thereafter the pressure fell, and the weather became increasingly cyclonic, with mainly southwesterly winds becoming fresh or strong at times. At Shoreham Airport,  southwesterly winds gusted to 32 knots (37 mph) on the afternoon of the 11th, but the next brisk winds were not until the 23rd when 30 knot (34 mph) southerly gusts were recorded in the evening. The 24th was a breezy day with southwesterly gusts peaking at 31 knots (35 mph) in the late afternoon.  The breezy weather persisted with 33 knots (38 mph) occurring during the afternoon of the 25th. Gusts of 30 knots (34 mph) were measured on the 26th, and the 27th was windier with 38 knots (43 mph) from the southwest during the afternoon.  There was no let up as southwesterly gusts exceeded 30 knots (34 mph) on the 28th, with 40 knots (46 mph) occurring early on the 29th. This was the highest gust of the month and the 30th was much calmer.    

Fog

There was no fog observed in this part of Shoreham during September. 

Statistics for September 2019