Mild and Rather Wet 

Temperatures

The average maximum temperature during December 2019 in Shoreham was 9.6 Celsius (50F), and that was over 1 Celsius (<2F) above normal for the time of year.  The average minimum temperature was 4.7 Celsius (41F), and that was under 1 Celsius above the December normal.    

The highest temperature recorded during the month was 12.4 Celsius (54F) on the 19th, but there were 12 other days when the maximum was above 10 Celsius (50F), including 4 days with highs above 11 Celsius (52F). There were a further 10 days when the temperature exceeded 9 Celsius, and cold days were few and far between. The first 4 days of the month had minimum temperatures below 8 Celsius (46F), but there was only 1 other day below this figure before the end of the year. On the 2nd a high of 6.3 Celsius (43F) occurred,  the only day of the month with a minimum below 7 Celsius (45F).

No especially mild nights were noted during December, but on 2 occasions the temperature stayed above 10 Celsius (50F).  On both the 6th and 19th the minimum temperature was 10.3 Celsius (50F). There were 2 more nights with minima above 9 Celsius (48F), and a further 4 with lows above 7 Celsius (45F). Night-time temperatures were variable throughout the month, although the lowest values were generally during the first fortnight of December. On 9 occasions the temperature fell below 3 Celsius (37F), but only 3 of these colder nights occurred after the 12th. The first 12 nights of December had 6 nights with minima below 1 Celsius (34F), but with only 1 of these nights having a low under minus 1 Celsius (30F). On the 5th,  minus 2.4 Celsius (28F) was measured, the coldest night of the month. 

The sea temperature slowly fell from 10 or 11  Celsius (50-52F) at the beginning of the month to 9 Celsius (48F) by the third week. where it remained for the rest of December.

Frost

A total of 3 air frosts were recorded during December. Apart from on the 5th, air temperatures dipped below freezing on both the 10th and 12th. However, frost was very slight with lows of minus 0.3 Celsius (32F) and 0.2 Celsius (32F) respectively. There were 13 grass frosts during the month, and although 6 of these occurred after mid month, they were slight,  with grass minima staying above minus 3 Celsius (27F). Grass lows were under minus 3 on 4 nights earlier in the month, with the lowest reading of minus 4.4 Celsius (24F) occurring on the 5th.    

Rain

A total of 97.8  millimetres (3.9 ins.) of rain fell during December and that was about 25% above the monthly average. There were 21 days of measurable rain, and that was around 5 days above normal for December. No measurable rain fell on the first 4 days of the month, but then the 9th was the sole dry day until the 27th. Initially rain was not particularly heavy, but over 6 millimetres (0.25ins.) fell on 7th with a further 8 millimetres (0.3 ins.) on the 12th. In the week before Christmas spells of rain falling on the totally saturated ground led to extensive flooding on the 21st. Although amounts were not remarkable, there were nearly 9 millimetres (0.35 ins.) on the 16th, over 8 millimetres (0.3 ins.) on the 18th, and 17.6 millimetres (0.7 ins.) on the 19th. This was topped up by nearly 7 millimetres (0.3 ins.) on the 19th and close on 9 millimetres (0.35 ins.) on the 21st. Thereafter, rain was lighter, although 7 millimetres (0.3 ins.) were recorded on the 26th.   The last 5 days of month were dry apart from 0.2 millimetres (0.01 ins) of dew on the last day of the month. 

Hail

Small hail was observed in Shoreham during a mid-afternoon shower on the 11th.

Thunder

No thunder was heard in Shoreham in December.

Snow

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

Wind

Southwesterly and northwesterly winds predominated during December with twice as many sou’westers as nor’westers. Early and late in the month pressure was relatively high and winds were mainly light or moderate, but the second and third weeks were very changeable and cyclonic with winds strong at times. At Shoreham Airport, gusts exceeded 30 knots (34 mph) during the 6th, peaking at 33 knots (38 mph), with 39 knots (44 mph) on the evening of the 8th,  with 41 knots (47 mph) occurring overnight into the 9th. A gust of 44 knots (50 mph) occurred on the passage of a cold front during the evening of the 10th, with blustery showers creating a gust of 37 knots (42 mph) around midday on the 11th. In a very breezy period, gusts between 34 and 39 knots (39-45 mph)  occurred on each of the following 4 days. Southwesterly gusts reached 34 knots (39 mph) early on the 21st. Apart from gusts of 33 knots (38 mph) on the afternoon of the 26th, there were no more gusts exceeding 30 knots (34 mph) during the remainder of the month.    

Fog

On the 30th there was fog until after mid morning. 

Statistics for November 2019