September 2021

A September shimmery seascape over the border in Cornwall

Summer lasted right through until the 27th then much cooler and wetter. Warmer than normal with around average rainfall. Slightly less sunnier than usual.

Summary for September 2021
Mean Max: 21.5C (+2.4C)
Mean Min: 10.9C (+0.0C)
Mean: 16.2C (+1.2C)
High Max: 28.2C 7th
Low Max: 15.9C 28th
High Min: 19.1C 8th
Low Min: 5.2C 29th
Mean Grass Min: 8.9C  
Grass Min: 2.2C 29th
Days  >25C 2 Days  
Days >20C 23 Days  
Nights  >15C 3 Days  
Nights  >10C 16 Days  
Rain Total (gauge): 57.8 mm (102%)
Rain Total (tipping bucket): 55.4 mm (98%)
Rain Days >0.2 mm: 9 Days  
Rain Days >1.0 mm: 7 Days  
Max 24 hrs: 19.0 mm 28th
Days without any rain: 21  
Air Frost: 0 Days  
Grass Frost: 0 Days  
Snow Falling: 0 Days  
Snow (50%) @ 9am: 0 Days  
Ice Days: 0 Days  
Thunder Heard: 0 Days  
Hail <5 mm: 0 Days  
Hail >5 mm: 0 Days  
Fog @ 9am: 0 Days  
Total Monthly Sunshine: 171.6 Hours (88%)
Most Sunshine in a Day: 12.6 Hours 6th
Average Daily Sunshine: 5.7 Hours  
Sunless Days: 0 Days  
Cloudless Days: 0 Days  
Total Possible Sunshine: 378.0 Hours  
Percentage of Total Sun: 45%  
Average Sunny Interval: 19.8 mins
Maximum UV Index: 5.8 6th
Mean Soil Temp @ 10 cm: 16.7C  
Min Soil Temp @ 10 cm: 14.0C 30th
Max Soil Temp @ 10 cm: 18.5C 10th
Mean Soil Temp @ 30 cm: 16.6C  
Min Soil Temp @ 30 cm: 14.5C 30th
Max Soil Temp @ 30 cm: 17.8C 10th
Mean Soil Temp @ 100 cm: 16.1C  
Min Soil Temp @ 100 cm: 15.6C 30th
Max Soil Temp @ 100 cm: 16.6C 10th
Ave 10 Min Wind >39 mph: 0.00 Days  
N: 5.14 Days 17%
NE: 2.05 Days 7%
E: 1.39 Days 4%
SE: 1.28 Days 4%
S: 3.81 Days 12%
SW: 3.60 Days 12%
W: 1.04 Days 3%
NW: 3.19 Days 10%
Calm: 8.49 Days 27%
Wind Chill Low: 4.8C 29th
Mean Wind: 2.3 mph  
Max Gust: 43 mph 28th
Mean Cloud Cover: 50%  
Mean RH @ 9am: 96%  
Rain >0.1mm/hour: 12.4 Hours  
Frost Duration: 0.0 Hours  
Air Frost in a Day: 0.0 Hours 1st
Mean Sea Temperature: 17.9C (-0.1C)
Normal for Month: 18.0C  
Max Sea Temperature: 21.5C 6th
Min Sea Temperature: 17.0C 30th
Mean Pressure @ 9am: 1018.4 hPa  
Mean Pressure: 1018.0 hPa  
Max Pressure: 1032.0 hPa 21st
Min Pressure: 1000.5 hPa 27th
Max Change in 24 hours: 17.0 hPa 27th
Radiation Daily Mean: 12.06 MJ/m  
Max Daily Value: 20.12 MJ/m 7th
Min Daily Value: 4.40 MJ/m 30th
Number of Days with Data: 30 Days  
1-Hour Maximum: 673 W/m 3rd 
Starting Time of the Hour:   13:00
Max Dewpoint: 20.7C 6th
Min Dewpoint: 4.5C 29th
Mean Dewpoint: 13.4C  
Max Humidity: 100% 6th
Min Humidity: 45% 7th
Mean Humidity: 84%  
 
Weather Data for Otter Valley, Devon. September 2021
  Temp oC Grass Hum (%) Soil oC (cm) Soil DP (oC) Wind (mph) Rain Air (hPa) W/m UV Sun Frost Sea Observations
  Min Max Min Min Max 10 30 100 (cb) Min Max Max Ave Run mm Min Max Max Max Hours Hours Temp
1 14.1 18.6 11.7 71 89 16.8 16.8 16.1 0.0 10.6 13.9 18 2.8 68 0.0 1028 1031 283 2.8 1.6 0.0 17.6 Sunny intervals all day
2 14.7 19.2 13.3 73 85 16.9 16.7 16.1 0.0 11.3 14.7 16 2.4 58 0.0 1024 1030 477 4.4 2.8 0.0 17.4 Sunny intervals all day
3 8.5 24.0 5.6 65 99 16.7 16.7 16.1 0.0 7.6 17.9 12 1.7 42 0.0 1018 1025 822 5.6 8.1 0.0 17.6 Sunny intervals all day
4 8.3 23.2 6.7 71 99 16.6 16.7 16.1 0.0 7.6 18.1 14 1.4 33 0.0 1016 1019 643 5.2 12.5 0.0 17.8 Sunny all day
5 12.4 23.8 10.0 75 98 17.1 16.7 16.1 0.0 11.5 19.7 12 1.3 32 0.0 1017 1021 608 5.4 6.5 0.0 17.9 Sunny intervals all day
6 11.4 27.7 9.4 61 100 17.2 16.9 16.1 0.0 10.9 20.7 11 1.2 29 0.0 1021 1023 621 5.8 12.6 0.0 18.7 Sunny all day
7 12.1 28.2 10.0 45 99 17.3 17.1 16.1 0.0 11.5 18.6 18 1.6 38 0.0 1015 1023 629 5.6 12.1 0.0 17.9 Sunny all day
8 19.1 23.7 14.4 59 93 17.9 17.2 16.1 0.0 14.5 19.5 17 2.9 70 0.6 1009 1015 673 5.3 2.2 0.0 17.9 Sunny intervals all day
9 14.6 20.3 12.2 92 99 18.1 17.6 16.1 0.0 13.5 19.7 17 2.0 47 10.8 1006 1010 526 3.8 0.7 0.0 18.2 Brief sunny intervals all day
10 16.5 20.4 13.9 82 99 18.5 17.8 16.6 0.0 15.7 18.0 16 1.8 44 1.4 1008 1015 366 3.6 0.6 0.0 18.4 Brief sunny intervals all day
11 9.6 21.2 7.2 63 100 17.9 17.6 16.5 0.0 8.8 15.9 14 1.6 38 0.0 1015 1019 771 5.5 6.0 0.0 18.0 Sunny intervals all day
12 9.2 21.2 7.2 73 99 17.0 17.1 16.3 0.0 8.5 16.8 11 1.1 27 0.0 1018 1020 699 5.5 8.6 0.0 18.0 Sunny intervals all day
13 13.1 20.9 12.2 78 99 17.3 17.2 16.5 0.0 12.4 17.5 11 0.7 16 1.4 1014 1019 656 4.9 3.8 0.0 18.0 Sunny intervals all day
14 14.6 20.3 11.1 82 97 17.6 17.2 16.4 0.0 13.4 17.6 11 2.0 47 1.2 1011 1014 482 4.5 3.2 0.0 18.0 Sunny intervals all day
15 9.4 23.2 7.8 66 99 17.1 17.1 16.2 0.0 8.9 17.6 13 1.2 29 0.0 1012 1017 796 5.1 6.5 0.0 18.1 Sunny intervals all day
16 12.3 21.9 10.6 74 99 16.9 17.0 16.2 0.0 11.8 17.7 12 0.8 19 0.0 1017 1019 835 5.3 2.3 0.0 18.3 Sunny intervals all day
17 10.1 21.6 8.3 69 100 16.9 16.9 16.1 0.0 9.3 17.8 18 2.4 57 0.0 1012 1017 740 5.2 4.1 0.0 18.2 Sunny intervals all day
18 15.4 23.1 13.3 72 96 17.3 17.0 16.1 0.0 14.2 19.3 15 1.0 25 0.0 1012 1013 747 5.3 4.6 0.0 18.3 Sunny intervals all day
19 11.6 21.5 8.9 62 99 17.3 17.2 16.1 0.0 10.2 16.0 17 2.5 60 4.0 1013 1019 781 4.7 9.3 0.0 18.1 Sunny intervals all day
20 5.4 22.7 6.1 53 100 16.2 16.5 16.1 0.0 4.8 14.1 14 1.9 45 0.0 1019 1028 653 4.4 11.7 0.0 17.9 Sunny all day
21 7.6 23.1 8.3 59 99 16.0 16.1 16.1 0.0 7.0 16.1 11 2.0 48 0.0 1028 1032 583 4.7 11.7 0.0 18.0 Sunny all day
22 7.3 21.8 8.3 64 99 15.9 15.8 16.1 0.0 6.7 16.7 11 1.3 32 0.0 1026 1031 719 4.9 6.4 0.0 18.0 Sunny intervals all day
23 8.1 21.6 7.2 78 100 16.0 15.8 16.1 0.0 7.0 18.2 14 1.4 34 0.0 1020 1026 589 3.9 2.5 0.0 17.9 Sunny intervals all day
24 8.0 22.5 8.3 73 100 15.7 15.7 16.1 0.0 7.2 17.9 11 0.7 17 0.0 1016 1021 661 4.8 6.4 0.0 18.0 Sunny intervals all day
25 13.9 19.2 12.8 88 99 16.4 15.9 15.9 0.0 12.9 17.9 9 0.5 12 0.0 1012 1017 286 2.5 0.3 0.0 18.1 Brief sunny intervals all day
26 9.3 21.4 7.8 76 100 15.9 16.0 15.9 0.0 8.8 17.9 21 3.4 80 0.0 1010 1012 789 4.6 4.7 0.0 18.0 Sunny intervals all day
27 10.6 18.4 3.9 70 98 15.9 16.1 15.8 0.0 8.5 16.7 34 6.9 165 16.6 1001 1018 642 4.1 9.1 0.0 17.8 Sunshine & showers
28 8.8 15.9 6.1 90 99 15.0 15.7 15.9 0.0 7.8 14.9 43 6.4 154 19.0 1010 1018 294 2.6 0.2 0.0 17.5 Heavy showers all day, windy
29 5.2 17.0 2.2 56 100 14.2 15.2 15.8 0.0 4.5 10.6 19 2.5 63 0.4 1012 1028 670 3.7 10.2 0.0 17.3 Sunny intervals all day
30 6.2 16.9 2.8 87 99 14.0 14.5 15.6 0.0 5.3 15.5 34 8.7 200 0.0 1015 1028 227 2.0 0.2 0.0 17.1 Cloudy all day
10.9 21.5 8.9 71 98 16.7 16.6 16.1 0.0 9.8 17.1 16 2.3 1630 55.4 1015 1021 609 4.5 171.6 0.0 17.9  
UV Light | Month So Far | Year So Far | Recording Data | Time-Lapse Videos | World Weather | Met Office 5-Day | Humidity Calculation | Links