Very Wet and Mild
Temperatures
The average maximum temperature during October 2021 in Shoreham was 16.9 Celsius (63F), and that was over 1 Celsius (2F) above normal for the time of year. The average minimum temperature was 10.6 Celsius (51F), and that was close to 1 Celsius (2F) above the October average. It appears to have been the warmest October in the area since 2006.
The highest temperature recorded during the month was 20.4 Celsius (69F) on the 9th, but the temperature reached 19.2 Celsius (67F) on the 14th and 19.6 Celsius (68F) on the 19th. Maxima were 17 Celsius (63F), or more, on a further 14 days. Unsurprisingly, the highest temperatures generally occurred early in the month, with only 1 high above 17 Celsius after the 20th. There were no cold days during October. In fact, only 3 days had temperatures below 15 Celsius (59F). The 22nd and 23rd had highs of 14.1 Celsius (57F) and 14.8 Celsius (59F) respectively, but the coolest day of the month was on the 21st when a high of 12.8 Celsius (55F) was recorded.
There were several very mild nights during October. On the 19th, a minimum of 16.5 Celsius (62F) was recorded, and 15.7 Celsius (60F) occurred on the following night. A further 5 nights had minima above 13 Celsius (55F), with 3 of these very mild nights occurring in the last week of October. There were only a few fairly cold nights. Although 13 nights had lows under 10 Celsius (50F), only 5 had minima below 7 Celsius (45F), and just 1 dipped below 6 Celsius (43F). That was on the 22nd, when the temperature fell to 3.4 Celsius (38F).
The sea temperature slowly fell from 18 Celsius (64F) at the beginning of October, to 14 or 15 Celsius (57-59F) at the end of the month.
Frost
No air frost occurred during October, but there was a grass frost on the 22nd with the temperature falling to minus 0.6 Celsius (31F). The next lowest grass temperature was 2.8 Celsius (37F) recorded on both the 11th and 12th.
Rain
Rainfall in October amounted to 187.4 millimetres (7.4 ins.) which was around double the average for the month. Although wetter in October last year, this year it was probably amongst the top ten wettest Octobers during the last 100 years. Measurable rain fell on 20 days, which was 2 days above the average, and wet days (when 1 millimetre (0.04 ins.), or more, of rain falls) numbered 12, and that was 1 day below the average. The month began very wet, with 28.2 millimetres (1.1 ins.) of rain falling on the 2nd, a further 13 millimetres (0.5 ins.) on the 3rd, followed by 33.4 millimetres (1.3 ins.) on the 4th. A relatively dry spell occurred between the 5th and 17th with only 2.2 millimetres (<0.1 ins.) of rain measured. However, another very wet interlude yielded 10.8 millimetres (0.4 ins.) on the 18th, followed by 22.8 millimetres (0.9 ins.) on the 19th, and in turn the wettest day of the month: on the 20th, a total of 36.4 millimetres (1.4 ins.) was measured. After 3 completely dry days, the unsettled weather resumed, and although amounts of rain were initially small, there were over 33 millimetres (1.3 ins.) in the 3 days beginning on the 28th, with the largest total of 12.8 millimetres (0.5 ins.) occurring on the 30th.
Hail
No hail was observed in this part of Shoreham.
Thunder
No thunder was heard in this part of Shoreham.
Snow
No sleet or snow was observed this month in Shoreham.
Wind
High pressure was dominant from the end of the first week of October to the beginning of the third week. During this period, winds were mainly light, otherwise, Atlantic westerlies prevailed, with winds from between southwest and northwest and often quite strong. At Shoreham Airport, the month began with southwesterly winds gusting over 35 knots (40 mph), with a peak gust of 37 knots (42 mph) occurring just after dawn. Southerly winds on the 2nd increased in strength during the afternoon, culminating in a gust of 44 knots (50 mph) early in the evening. Southwesterly gusts of 38 knots (43 mph) occurred on the afternoon of the 3rd, with an isolated squally gust of 43 knots (49 mph) occurring during a heavy shower on the morning of the 4th. The windy weather continued, with southerly gusts of 35 knots (42 mph) recorded overnight on the 5th, but it then became much quieter until the 20th, which was a windy day with many south to southwesterly gusts exceeding 35 knots (40 mph), and one of 40 knots (46 mph) late in the evening. The 29th was another windy day with a gust of 37 knots (42 mph) occurring late in the morning. The last day of the month was the windiest, especially during the morning, and a south-southeasterly gust of 50 knots (57 mph) was recorded in the late morning.
Fog
There was fog overnight on the 8th, this clearing late in the morning on the 9th.
Statistics for October 2021
| Reporting Site | Highest Temp | Lowest Temp | Rain Total (mm) | Wettest | Rain days |
| Shoreham A/P | 19.2 | 2.3 | 121 | 21 | 18 |
| Thorney Island | 18.9 | 4.0 | 125 | 23 | 15 |
| Gatwick A/P | 19.0 | 3.0 | 146 | 27 | 15 |
| Herstmonceux | 21.1 | 3.6 | 152 | 30 | 17 |
| Bournemouth (Hurn) | 20.1 | 1.9 | 144 | 35 | 20 |
| Middle Wallop | 19.5 | 3.5 | 146 | 33 | 19 |
| Dieppe | 22.3 | 3.6 | 77 | 33 | 17 |