site -09GMT MSL Pressure- --Rainfall-- --Maximum Temp--- --Minimum Temp--- --Sunshine-- Mean Temp Rain -Sun Pres09
mean high low Total 12hMx Mean High Low Mean High Low Total Max Temp Anom Anom
mb mb mb mm mm C C C C C C hr hr C C % % mb
03002 996.7 996.7 996.7 0.0 0.0 17.2 17.2 17.2 13.9 13.9 13.9 0.0 ***** 15.6 +4.2 0 Baltasound
03005 995.0 995.0 995.0 0.0 ***** 0 -16.1 Lerwick
03006 0.0 ***** Sella Ness
03008 993.9 993.9 993.9 0.0 0.0 15.4 15.4 15.4 14.0 14.0 14.0 0.0 ***** 14.7 +3.3 0 0 Fair Isle
03010 0.0 ***** Sule Skerry
03011 0.0 ***** North Rona
03014 0.0 ***** Foula
03017 990.3 990.3 990.3 13.6 13.6 13.6 0.0 ***** 0 Kirkwall
03023 983.5 983.5 983.5 12.9 12.9 12.9 0.0 ***** South Uist Range
03026 986.8 986.8 986.8 3.0 3.0 16.5 16.5 16.5 13.4 13.4 13.4 0.0 ***** 14.9 +2.8 3 0 -24.4 Stornoway
03031 988.6 988.6 988.6 2.0 2.0 18.0 18.0 18.0 11.4 11.4 11.4 0.0 ***** 14.7 +3.9 2 0 Loch Glascarnoch
03034 987.2 987.2 987.2 2.0 2.0 18.9 18.9 18.9 13.1 13.1 13.1 0.0 ***** 16.0 +3.3 2 Aultbea
03037 0.0 ***** Lusa
03039 0.0 ***** Bealach No Ba
03041 0.0 ***** Aonach Moor
03044 988.8 988.8 988.8 0.2 0.2 20.2 20.2 20.2 14.7 14.7 14.7 0.0 ***** 17.5 +5.9 0 0 Altnaharra
03047 989.9 989.9 989.9 6.0 6.0 15.9 15.9 15.9 11.4 11.4 11.4 0.0 ***** 13.6 +2.5 5 Tulloch Bridge
03055 0.0 ***** Rackwick
03062 989.4 989.4 989.4 0.0 0.0 20.2 20.2 20.2 14.5 14.5 14.5 0.0 ***** 17.4 +5.1 0 Tain Range
03063 989.5 989.5 989.5 0.0 ***** 0 Aviemore
03065 0.0 ***** Cairngorm
03066 989.2 989.2 989.2 15.1 15.1 15.1 0.0 ***** 0 Kinloss
03068 989.5 989.5 989.5 14.5 14.5 14.5 0.0 ***** Lossiemouth
03070 0.0 ***** Glenlivet
03072 0.0 ***** Cairnwell
03075 990.0 990.0 990.0 14.5 14.5 14.5 0.0 ***** 0 Wick
03080 991.9 991.9 991.9 0.6 0.6 18.2 18.2 18.2 12.3 12.3 12.3 0.0 ***** 15.2 +3.5 1 Aboyne
03088 992.6 992.6 992.6 0.2 0.2 17.0 17.0 17.0 13.0 13.0 13.0 0.0 ***** 15.0 Inverbervie
03091 992.9 992.9 992.9 0.4 0.4 18.8 18.8 18.8 13.7 13.7 13.7 0.0 ***** 16.2 +3.7 1 0 -19.8 Aberdeen Dyce
03092 0.0 ***** Peterhead Harbour
03094 0.0 ***** Rosehearty
03171 991.7 991.7 991.7 13.4 13.4 13.4 0.0 ***** 0 Leuchars
03100 986.3 986.3 986.3 4.0 4.0 16.9 16.9 16.9 13.1 13.1 13.1 0.0 ***** 15.0 +2.2 4 0 -26.1 Tiree
03105 989.8 989.8 989.8 2.0 2.0 17.8 17.8 17.8 12.6 12.6 12.6 0.0 ***** 15.2 Port Ellen
03111 990.3 990.3 990.3 4.0 4.0 18.2 18.2 18.2 12.8 12.8 12.8 0.0 ***** 15.5 Machrihanish
03116 0.0 ***** Dalmally
03120 0.0 ***** Lochranza
03132 993.7 993.7 993.7 13.7 13.7 13.7 0.0 ***** 0 West Freugh
03134 991.0 991.0 991.0 4.0 4.0 17.5 17.5 17.5 12.9 12.9 12.9 0.0 ***** 15.2 +2.3 4 0 Glasgow Bishopton
03136 992.6 992.6 992.6 13.1 13.1 13.1 0.0 ***** 0 Prestwick
03139 0.0 ***** 0 Saughall
03144 991.7 991.7 991.7 2.0 2.0 18.3 18.3 18.3 13.2 13.2 13.2 0.0 ***** 15.8 +3.1 3 Strathallan
03148 0.0 ***** Glen Ogle
03153 992.6 992.6 992.6 0.0 0.0 17.4 17.4 17.4 13.0 13.0 13.0 0.0 ***** 15.2 +2.3 0 Dundrennan
03155 991.8 991.8 991.8 2.0 2.0 17.4 17.4 17.4 12.2 12.2 12.2 0.0 ***** 14.8 +3.0 3 Drumalbin
03158 993.7 993.7 993.7 0.0 0.0 19.7 19.7 19.7 12.8 12.8 12.8 0.0 ***** 16.2 +3.4 0 0 Charterhall
03162 993.2 993.2 993.2 31.0 31.0 16.2 16.2 16.2 11.4 11.4 11.4 0.0 ***** 13.8 +2.4 23 0 -21.2 Eskdalemuir
03166 992.3 992.3 992.3 13.1 13.1 13.1 0.0 ***** 0 Edinburgh Gogarbank
03176 0.0 ***** Carterhouse
03204 994.5 994.5 994.5 0.0 0.0 19.3 19.3 19.3 14.5 14.5 14.5 0.0 ***** 16.9 +2.9 0 0 Ronaldsway
03210 993.9 993.9 993.9 4.0 4.0 17.3 17.3 17.3 13.5 13.5 13.5 0.0 ***** 15.4 +2.2 4 St Bees Head
03212 994.1 994.1 994.1 4.0 4.0 18.0 18.0 18.0 13.1 13.1 13.1 0.0 ***** 15.6 +2.4 3 Keswick
03214 994.7 994.7 994.7 2.0 2.0 18.8 18.8 18.8 14.4 14.4 14.4 0.0 ***** 16.6 Walney Island
03220 993.7 993.7 993.7 3.0 3.0 18.3 18.3 18.3 14.2 14.2 14.2 0.0 ***** 16.2 +2.8 4 0 Carlisle
03224 994.7 994.7 994.7 11.1 11.1 11.1 0.0 ***** Spadeadam
03225 994.9 994.9 994.9 11.0 11.0 16.9 16.9 16.9 11.9 11.9 11.9 0.0 ***** 14.4 +2.8 8 Shap Fell
03226 995.1 995.1 995.1 4.0 4.0 17.5 17.5 17.5 12.2 12.2 12.2 0.0 ***** 14.9 +2.6 5 Warcop Range
03227 0.0 ***** Great Dun Fell
03348 0.0 ***** 0 Woodford
03351 0.0 ***** Rostherne
03230 994.5 994.5 994.5 0.4 0.4 17.8 17.8 17.8 8.9 8.9 8.9 0.0 ***** 13.3 +1.8 1 Redesdale
03238 994.9 994.9 994.9 12.3 12.3 12.3 0.0 ***** Albermarle
03240 995.2 995.2 995.2 0.0 0.0 20.5 20.5 20.5 13.0 13.0 13.0 0.0 ***** 16.8 +3.6 0 0 Boulmer
03257 996.8 996.8 996.8 1.0 1.0 20.8 20.8 20.8 12.1 12.1 12.1 0.0 ***** 16.5 +2.9 2 0 -17.9 Leeming
03261 0.0 ***** Dishforth
03265 996.6 996.6 996.6 11.9 11.9 11.9 0.0 ***** Topcliffe
03266 0.0 ***** Linton-on-Ouse
03275 996.3 996.3 996.3 0.0 ***** Loftus
03281 2.0 2.0 0.0 ***** 2 Fylingdales
03292 998.8 998.8 998.8 1.0 1.0 20.4 20.4 20.4 14.5 14.5 14.5 0.0 ***** 17.5 +3.3 2 Bridlington
03339 0.0 ***** Skipton
03344 997.2 997.2 997.2 0.0 ***** Bingley
03346 3.0 3.0 0.0 ***** Emley Moor No.2
03345 0.0 ***** Emley Moor
03354 0.0 ***** 0 Nottingham Wea Cen
03355 0.0 ***** Church Fenton
03373 0.0 ***** Scampton
03377 999.6 999.6 999.6 0.2 0.2 21.4 21.4 21.4 11.7 11.7 11.7 0.0 ***** 16.5 +2.2 0 0 -15.7 Waddington
03379 998.9 998.9 998.9 0.0 ***** 0 Cranwell
03382 999.0 999.0 999.0 4.0 4.0 21.3 21.3 21.3 13.4 13.4 13.4 0.0 ***** 17.3 +3.2 7 0 Leconfield
03385 999.9 999.9 999.9 22.3 22.3 22.3 12.6 12.6 12.6 0.0 ***** 17.5 Donna Nook
03391 999.2 999.2 999.2 0.0 ***** Coningsby
03392 999.5 999.5 999.5 0.0 ***** Wainfleet
03302 997.8 997.8 997.8 0.0 ***** 0 -17.2 Valley
03301 996.3 996.3 996.3 0.0 0.0 18.5 18.5 18.5 14.1 14.1 14.1 0.0 ***** 16.3 Raf Mona
03305 996.3 996.3 996.3 13.0 13.0 16.0 16.0 16.0 13.2 13.2 13.2 0.0 ***** 14.6 +1.9 6 Capel Curig
03313 996.5 996.5 996.5 4.0 4.0 19.1 19.1 19.1 14.5 14.5 14.5 0.0 ***** 16.8 +2.8 5 Rhyl
03316 997.8 997.8 997.8 0.0 ***** Crosby
03318 995.7 995.7 995.7 1.0 1.0 19.6 19.6 19.6 14.0 14.0 14.0 0.0 ***** 16.8 +2.7 1 0 Blackpool
03321 996.8 996.8 996.8 4.0 4.0 20.2 20.2 20.2 13.8 13.8 13.8 0.0 ***** 17.0 +2.9 6 0 Hawarden
03405 999.4 999.4 999.4 0.0 ***** 0 Aberdaron
03409 996.5 996.5 996.5 6.0 6.0 17.0 17.0 17.0 13.6 13.6 13.6 0.0 ***** 15.3 Bala
03410 996.7 996.7 996.7 3.0 3.0 15.6 15.6 15.6 11.4 11.4 11.4 0.0 ***** 13.5 +1.3 2 0 Lake Vrynwy
03502 1000.2 1000.2 1000.2 0.0 ***** 0 -15.5 Aberporth
03503 997.9 997.9 997.9 9.0 9.0 19.0 19.0 19.0 13.6 13.6 13.6 0.0 ***** 16.3 Trawscoed
03507 1000.4 1000.4 1000.4 0.0 ***** Sennybridge
03604 999.1 999.1 999.1 1.0 1.0 18.9 18.9 18.9 14.1 14.1 14.1 0.0 ***** 16.5 +1.8 1 0 Milford Haven
03605 999.1 999.1 999.1 2.0 2.0 18.9 18.9 18.9 14.3 14.3 14.3 0.0 ***** 16.6 +2.3 3 Pembrey Sands
03609 0.0 ***** Mumbles
03716 1000.1 1000.1 1000.1 0.0 0.0 19.7 19.7 19.7 15.4 15.4 15.4 0.0 ***** 17.5 +2.7 0 0 St Athan
03330 998.4 998.4 998.4 0.0 ***** Leek Thorncliffe
03414 998.7 998.7 998.7 0.0 ***** 0 Shawbury
03520 998.4 998.4 998.4 0.8 0.8 19.3 19.3 19.3 10.9 10.9 10.9 0.0 ***** 15.1 +1.3 1 0 Shobdon
03522 1000.5 1000.5 1000.5 0.0 ***** Hereford Credenhill
03527 0.0 ***** Great Malvern
03529 999.9 999.9 999.9 0.4 0.4 22.5 22.5 22.5 13.9 13.9 13.9 0.0 ***** 18.2 +3.6 1 0 Pershore
03535 999.3 999.3 999.3 0.0 ***** 0 Coleshill
03544 999.6 999.6 999.6 0.2 0.2 20.6 20.6 20.6 12.7 12.7 12.7 0.0 ***** 16.6 +2.3 0 Church Lawford
03628 0.0 ***** 0 Filton
03647 1000.5 1000.5 1000.5 0.0 ***** 0 Little Rissington
03649 1001.3 1001.3 1001.3 0.0 ***** 0 Brize Norton
03658 1001.4 1001.4 1001.4 5.0 5.0 20.7 20.7 20.7 12.7 12.7 12.7 0.0 ***** 16.7 +2.4 10 0 Benson
03660 0.0 ***** High Wycombe
03453 0.0 ***** Cottesmore
03462 1000.0 1000.0 1000.0 0.4 0.4 22.7 22.7 22.7 12.3 12.3 12.3 0.0 ***** 17.5 +3.0 1 0 Wittering
03469 1000.8 1000.8 1000.8 0.0 0.0 22.7 22.7 22.7 12.9 12.9 12.9 0.0 ***** 17.8 +3.2 0 Holbeach
03482 1000.6 1000.6 1000.6 0.0 ***** 0 Marham
03488 1001.6 1001.6 1001.6 0.6 0.6 22.2 22.2 22.2 13.5 13.5 13.5 0.0 ***** 17.9 +2.8 1 Weybourne
03931 1002.3 1002.3 1002.3 2.0 2.0 21.9 21.9 21.9 13.1 13.1 13.1 0.0 ***** 17.5 Tibenham
03560 1001.1 1001.1 1001.1 3.0 3.0 21.4 21.4 21.4 12.1 12.1 12.1 0.0 ***** 16.8 +2.1 6 0 Bedford
03590 1002.8 1002.8 1002.8 2.0 2.0 21.7 21.7 21.7 13.7 13.7 13.7 0.0 ***** 17.7 +3.1 4 0 Wattisham
03684 1002.4 1002.4 1002.4 0.6 0.6 20.8 20.8 20.8 12.8 12.8 12.8 0.0 ***** 16.8 +2.1 1 Andrewsfield
03693 1003.4 1003.4 1003.4 0.0 ***** 0 Shoeburyness
03707 1002.5 1002.5 1002.5 0.0 ***** 0 Chivenor
03710 1000.9 1000.9 1000.9 5.0 5.0 16.0 16.0 16.0 11.4 11.4 11.4 0.0 ***** 13.7 +0.6 5 0 Liscombe
03740 1001.0 1001.0 1001.0 2.0 2.0 19.3 19.3 19.3 13.0 13.0 13.0 0.0 ***** 16.1 +1.9 4 0 -15.3 Lyneham
03743 1002.1 1002.1 1002.1 0.0 ***** Larkhill
03803 1005.2 1005.2 1005.2 0.0 ***** 0 Scilly/St. Marys
03808 1003.0 1003.0 1003.0 2.0 2.0 18.3 18.3 18.3 12.9 12.9 12.9 0.0 ***** 15.6 +0.9 3 0 -13.6 Camborne
03809 1004.5 1004.5 1004.5 0.0 ***** 0 Culdrose RNAS
03817 0.0 ***** St Mawgan
03823 1002.0 1002.0 1002.0 12.0 12.0 18.0 18.0 18.0 12.4 12.4 12.4 0.0 ***** 15.2 +1.2 12 Cardinham
03827 1002.6 1002.6 1002.6 0.4 0.4 20.2 20.2 20.2 14.2 14.2 14.2 0.0 ***** 17.2 +2.1 1 0 Plymouth
03839 0.0 ***** 0 Exeter
03840 1002.8 1002.8 1002.8 0.0 ***** 0 Dunkeswell
03853 1002.8 1002.8 1002.8 0.0 ***** 0 Yeovilton
03844 1001.9 1001.9 1001.9 3.0 3.0 20.4 20.4 20.4 13.9 13.9 13.9 0.0 ***** 17.1 Exeter AirportNo2
03930 1001.5 1001.5 1001.5 0.0 ***** Almondsbury
03857 1002.7 1002.7 1002.7 0.0 0.0 19.4 19.4 19.4 16.1 16.1 16.1 0.0 ***** 17.8 +2.0 0 0 Isle of Portland
03672 1002.3 1002.3 1002.3 0.0 ***** Northolt
03746 1001.9 1001.9 1001.9 0.0 ***** 0 Boscombe Down
03749 1001.8 1001.8 1001.8 0.6 0.6 21.4 21.4 21.4 13.3 13.3 13.3 0.0 ***** 17.4 +2.7 1 Middle Wallop
03761 1002.4 1002.4 1002.4 0.0 ***** 0 Odiham
03768 0.0 ***** 0 South Farnborough
03769 1003.2 1003.2 1003.2 0.0 ***** 0 Charlwood
03770 2.0 2.0 0.0 ***** St James Park
03772 1002.4 1002.4 1002.4 0.0 ***** 0 -13.8 Heathrow
03779 0.0 ***** London Weather Centr
03781 1003.0 1003.0 1003.0 3.0 3.0 19.3 19.3 19.3 12.9 12.9 12.9 0.0 ***** 16.1 +1.6 5 Kenley
03784 0.0 ***** Gravesend
03791 0.0 ***** Sheerness
03796 1004.7 1004.7 1004.7 19.0 19.0 19.0 15.2 15.2 15.2 0.0 ***** 17.1 Langdon Bay
03797 1004.2 1004.2 1004.2 0.0 ***** 0 -12.1 Manston
03862 1002.6 1002.6 1002.6 0.8 0.8 21.6 21.6 21.6 15.5 15.5 15.5 0.0 ***** 18.5 +4.0 1 0 -13.9 Bournemouth Hurn
03866 1003.2 1003.2 1003.2 0.8 0.8 18.7 18.7 18.7 15.6 15.6 15.6 0.0 ***** 17.2 St Catherines Point
03872 1003.1 1003.1 1003.1 3.0 3.0 20.5 20.5 20.5 15.1 15.1 15.1 0.0 ***** 17.8 +2.4 5 0 Thorney Island
03874 0.0 ***** Solent MRSC
03876 1003.8 1003.8 1003.8 5.0 5.0 20.0 20.0 20.0 14.5 14.5 14.5 0.0 ***** 17.2 +2.3 8 Shoreham
03882 1004.3 1004.3 1004.3 0.0 ***** 0 Herstmonceux
03894 1004.8 1004.8 1004.8 0.0 0.0 19.2 19.2 19.2 15.3 15.3 15.3 0.0 ***** 17.2 +1.6 0 0 -13.2 Guernsey Airport
03895 1005.1 1005.1 1005.1 0.0 0.0 20.5 20.5 20.5 15.3 15.3 15.3 0.0 ***** 17.9 Jersey Airport
03896 0.0 0.0 19.8 19.8 19.8 16.2 16.2 16.2 0.0 ***** 18.0 St Helier
03901 991.5 991.5 991.5 9.0 9.0 16.3 16.3 16.3 12.2 12.2 12.2 0.0 ***** 14.2 Thomastown
03903 0.0 ***** St Angelo
03904 992.0 992.0 992.0 0.0 ***** Castlederg
03907 989.8 989.8 989.8 4.0 4.0 17.5 17.5 17.5 12.4 12.4 12.4 0.0 ***** 14.9 Magilligan
03908 0.0 ***** 0 Ballykelly
03911 991.3 991.3 991.3 4.0 4.0 15.7 15.7 15.7 11.2 11.2 11.2 0.0 ***** 13.4 +1.5 4 Lough Fea
03915 992.0 992.0 992.0 0.0 ***** Port Glenone
03916 990.1 990.1 990.1 3.0 3.0 16.7 16.7 16.7 12.0 12.0 12.0 0.0 ***** 14.4 +1.9 3 0 Ballypatrick Forest
03917 991.7 991.7 991.7 3.0 3.0 17.5 17.5 17.5 12.6 12.6 12.6 0.0 ***** 15.1 +1.8 4 0 -22.3 Aldergrove
03923 992.0 992.0 992.0 12.0 12.0 17.2 17.2 17.2 11.9 11.9 11.9 0.0 ***** 14.6 +1.8 16 Glennane
03927 0.0 ***** Bangor Harbour
03953 1000.2 1000.2 1000.2 1.0 1.0 16.9 16.9 16.9 13.3 13.3 13.3 0.0 ***** 15.1 +1.0 1 -15.2 Valentia
03955 999.4 999.4 999.4 0.1 0.1 18.4 18.4 18.4 11.7 11.7 11.7 0.0 ***** 15.0 +1.7 0 0 -16.1 Cork Airport
03956 997.9 997.9 997.9 4.0 4.0 18.2 18.2 18.2 13.2 13.2 13.2 0.0 ***** 15.7 Johnstown Castle
03957 0.0 ***** Rosslare
03962 997.5 997.5 997.5 4.0 4.0 17.4 17.4 17.4 13.6 13.6 13.6 0.0 ***** 15.5 +1.3 5 0 -17.4 Shannon Airport
03967 995.2 995.2 995.2 2.0 2.0 16.9 16.9 16.9 13.1 13.1 13.1 0.0 ***** 15.0 +1.8 3 0 Casement Aerodrome
03969 994.9 994.9 994.9 0.3 0.3 17.4 17.4 17.4 13.6 13.6 13.6 0.0 ***** 15.5 +2.5 0 0 -19.9 Dublin Airport
03973 992.8 992.8 992.8 13.0 13.0 16.0 16.0 16.0 11.4 11.4 11.4 0.0 ***** 13.7 Connaught Airport
03976 992.4 992.4 992.4 1.0 1.0 16.2 16.2 16.2 13.8 13.8 13.8 0.0 ***** 15.0 +1.3 1 -21.3 Belmullet
03952 999.4 999.4 999.4 0.1 0.1 19.1 19.1 19.1 12.9 12.9 12.9 0.0 ***** 16.0 Roches Point
03970 993.9 993.9 993.9 9.0 9.0 11.4 11.4 11.4 0.0 ***** Claremorris
03971 994.5 994.5 994.5 2.0 2.0 16.0 16.0 16.0 12.0 12.0 12.0 0.0 ***** 14.0 3 Mullingar
03978 991.1 991.1 991.1 6.0 6.0 16.4 16.4 16.4 12.4 12.4 12.4 0.0 ***** 14.4 Finner
03961 997.0 997.0 997.0 1.0 1.0 19.1 19.1 19.1 13.5 13.5 13.5 0.0 ***** 16.3 Oak Park
03979 992.7 992.7 992.7 1.0 1.0 16.7 16.7 16.7 12.2 12.2 12.2 0.0 ***** 14.5 Ballyhaise
03966 996.4 996.4 996.4 3.0 3.0 16.8 16.8 16.8 13.0 13.0 13.0 0.0 ***** 14.9 Gurteen
03963 995.0 995.0 995.0 4.0 4.0 16.3 16.3 16.3 14.1 14.1 14.1 0.0 ***** 15.2 Mace Head
03951 1000.5 1000.5 1000.5 0.8 0.8 17.5 17.5 17.5 14.0 14.0 14.0 0.0 ***** 15.8 Sherkin Island
03980 988.4 988.4 988.4 3.0 3.0 17.2 17.2 17.2 12.7 12.7 12.7 0.0 ***** 15.0 +1.7 3 -24.7 Malin Head
site -09GMT MSL Pressure- --Rainfall-- --Maximum Temp--- --Minimum Temp--- --Sunshine-- Mean Temp Rain -Sun Pres
The data above are for the month of Sep 2025 ending at 18GMT on day 01.Averages refer to the period 1991-2020 in all cases.
09GMT MSL Pressure (mb) : mean, highest and lowest MSL pressure at 0900GMT
Rainfall (mm) : total starting 0600GMT/1st, and greatest 12-hour fall ending 06GMT or 18GMT
Maximum Temperature (degC) : for the period 06-18GMT, mean, highest and lowest
Minimum Temperature (degC) : for the period 18-06GMT, mean, highest and lowest
Sunshine (h) : total and highest daily value
Mean Temperature (degC) : the average of the mean maximum and mean minimum
Temperature anomaly (degC) : the departure from the climatological average
Rainfall percentage (%) : the monthly total as a percentage of the climatological average
Sunshine percentage (%) : the monthly total as a percentage of the climatological average
(an asterisk denotes site now uses a Kipp-Zonen instrument). This change was made
to the tables on 27.08.2008. Climatological averages are for 30-years of
pseudo-KZ observations in this case)
Pressure anomaly (mb) : the departure from the climatological average