Fairbanks Annual Summary 2015

 

 

Fairbanks Annual

Weather Review 2015

by

Gerd Wendler

Alaska Climate Research Center, Geophysical Institute, UAF

 

TEMPERATURE: The mean annual temperature in Fairbanks for 2015 (Figure 1) was 30.0°F, 2.3°F above the last normal of the mean of the last 3 decades. It was 1.2°F cooler than 2014, but nevertheless substantially above the long term mean. The data for Fairbanks go back to 1906, one of the longest unbroken meteorological records for Alaska. While the overall warming trend of about 2.5°F per century continued, this trend is anything but linear (Wendler and Shulski 2009). Actually, the warmest annual temperature ever measured occurred in 1926 with a temperature just above the freezing point.

Figure 1: 2015 temperatures of Fairbanks, Alaska.

 

In Figure 2, the deviations of the mean daily temperatures are presented. The highest temperature of the year occurred on the 6 July 2015 at 89°F, while the coldest temperature of -43°F was observed on the 26 and 27 January and again on the 2nd February 2015. This large temperature variation is typical for the continental climate of Interior Alaska, where summers are relatively warm, while winters can be really cold. There were 11 days with temperatures at or above 80°F, and 7 days with temperatures at or below -40°F.

 

Figure 2: The mean annual temperature course for Fairbanks and its deviation from normal for 2015.

 

In Table 1 the monthly temperature values as well as the departures from normal are presented. As could be estimated from the also Figure 2, it shows that the first 5 months of the year were too warm, especially May was very pleasant and observed a mean temperature of 55.3°F. The summer months were somewhat too cool, especially September being 2.5° below its long-term mean value. The last 3 months of the year were above normal again, especially October with a positive deviation of 7.6°F, resulting in a mean annual temperature of 30.0°F, 2°F below the freezing point.

Table 1: Monthly temperatures at Fairbanks for 2015, normal (30 year mean) temperatures and departures from the mean values.

Month

Temperature

Observed
(°F)

Normal
(°F)

Delta
(°F)

January

-6.5

-7.9

1.4

February

1.0

-1.3

2.3

March

15.5

11.4

4.1

April

36.8

32.5

4.3

May

55.3

49.4

5.9

June

59.8

60.4

-0.6

July

62.2

62.5

-0.3

August

54.6

56.1

-1.5

September

42.4

44.9

-2.5

October

31.8

24.2

7.6

November

9.1

2.6

6.5

December

-2.2

-4.1

1.9

 

Precipitation: The annual precipitation in Fairbanks was measured at 14.38", 3.57" above the expected value of 10.81". In Figure 3 the cumulative daily precipitation is

Figure 3: Cumulative daily precipitation for 2015, Fairbanks, Alaska.

 

given. The figure shows, the first 3 months ending up with a normal value, January and the first 2/3 of February being too dry, but thereafter the deficit is balanced towards the end of March. From 1 May to late July below normal precipitation values were observed. This, in combination with the far above temperatures in May, resulted in the drying out of the surface layer and a great number of forest fires. Only, by mid-September heavy rainfalls started and ended the year with a precipitation surplus. In Table 2 the monthly precipitation values for 2015 and the deviations from normal are shown. 

 

Table 2: Monthly precipitation at Fairbanks for 2015, normal (30 year mean) values and departures from the mean values.

Month

Precipitation

Observed
(in)

Normal
(in)

Delta
(in)

Delta
%

%

January

0.15

0.58

-0.43

-74%

26%

February

0.48

0.42

0.06

14%

114%

March

0.49

0.25

0.24

96%

196%

April

0.16

0.31

-0.15

-48%

52%

May

0.29

0.60

-0.31

-52%

48%

June

1.03

1.37

-0.34

-25%

75%

July

2.78

2.16

0.62

29%

129%

August

2.58

1.88

0.70

37%

137%

September

3.74

1.10

2.64

240%

340%

October

0.83

0.83

0.00

0%

100%

November

1.78

0.67

1.11

166%

266%

December

0.07

0.64

-0.57

-89%

11%

 

 

Precipitation can, of course, fall in liquid form (rain) mostly in summer and in solid form (snow) mostly in winter. While in summer the surface is normally dry again after a few hours or days, in winter it forms a snow cover, which normally last months. It has hence a great influence on the heat exchange between the atmosphere and the soil, as snow is a great insulator.

 

Table 3: Monthly snowfall at Fairbanks for 2015, normal (30 year mean) values and departures from the mean values.

Month

Snowfall

Observed
(in)

Normal
(in)

Delta
(in)

Delta
%

%

January

4.60

10.30

-5.70

-55%

45%

February

4.00

8.10

-4.10

-51%

49%

March

8.10

4.90

3.20

65%

165%

April

2.10

2.90

-0.80

-28%

72%

May

0.00

0.90

-0.90

-100%

0%

June

0.00

0.00

0.00

 

July

0.00

0.00

0.00

 

August

0.00

0.00

0.00

 

September

20.90

1.80

19.10

1061%

1161%

October

3.80

10.80

-7.00

-65%

35%

November

25.40

13.20

12.20

92%

192%

December

1.10

12.10

-11.00

-91%

9%

 

 

Two months stick out. The September 2015 (29th) was an absolute record in snowfall, and due to the heavy load on trees widespread electrical outages were reported. Again, November reported about twice the expected values. However, trees were at that time leafless, and causing less damage.

 

 

Reference: Wendler, G and M. Shulski, 2009, A Century of Climate Change for Fairbanks, Alaska, Arctic, 62(3), 295-300

 

 

Table 4: Climatological data of interest for 2015, Fairbanks, Alaska.

 

2015 by the Numbers

Statistic

Value

Mean Annual Temperature

30°F

     Departure from Normal

2.4°F

Highest Temperature

89°F (6 Jul)

Mean Highest Temperature

72.0°F (6 Jul)

Highs at or Above 80°F

11 days

Lowest Temperature

-43°F (26, 27 Jan, 2 Feb)

Mean Lowest Temperature

-36.0°F (26 Jan)

Lows at or Below -40°F

7 days

Total Precipitation

14.38 inches

     Departure from Normal

3.57 inches

Maximum 24hr Precipitation

0.81 inches (27 Jul)

Total Snowfall

70.0 inches

     Departure from Normal

5.0 inches

Maximum 24hr Snowfall

11.2 inches (29 Sep)

New Record Highs/Lows

5 / 0

New Record Precipitation/Snowfall

4 / 4

Heating Degree Days

12698

     Departure from Normal

-968

Cooling Degree Days

56

     Departure from Normal

-5

Growing Degree Days

1068

     Departure from Normal

7

Average Wind Speed

3.575 mph

Highest Wind Speed

50 mph at 260° (28 Feb)

End of Seasonal Snow Cover

18 Apr (7 days early)

Last Freeze

6 May (1 days late)

Greenup Day

3 May (7 days early)

First Freeze

2 Sep (9 days early)

Length of Growing Season

118 days

     Departure from Normal

10 days less

Establishment of Seasonal Snow Cover

29 Oct (20 days late)

Wildfire Area Burned

5,146,641 acres

       Human Caused

26,697 acres

       Lightning Caused

5,119,844 acres

Number of Wildland Fires

770

       Human Caused

353

       Lightning Caused

416

 

 

 

This information consists of preliminary climatological data compiled by the Alaska Climate Research Center, Geophysical Institute, University of Alaska Fairbanks. For more information on weather and climatology, contact the center at 474-7885 or visit the center web site at http://akclimate.org. Please report any errors to webmaster@akclimate.org.

 

 

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