This report describes the historical weather record at the Eielson Air Force Base (Fairbanks, Alaska, United States) during 1970. This station has records back to December 1947.
Fairbanks, Alaska has a humid subarctic continental climate with cool summers and no dry season. The area within 25 mi of this station is covered by forests (96%) and lakes and rivers (3%)
Daylight saving time (DST) was observed at Fairbanks, Alaska during 1970. There were two time changes during 1970:
1970 was not a leap year, so it has 365 days and no February 29th. The first leap year before 1970 was 1968 and the first after was 1972.
The summer and winter solstices and the spring and fall equinoxes mark the passing of the seasons. They fall on nearly the same day each year, with differences of a day or two depending on the year. In 1970 they occurred on:
|Spring Equinox||Saturday, 21 March 1970.|
|Summer Solstice||Sunday, 21 June 1970.|
|Fall Equinox||Wednesday, 23 September 1970.|
|Winter Solstice||Tuesday, 22 December 1970.|
The hottest day of 1970 was July 27, with a high temperature of 85°F. For reference, on that day the average high temperature is 67°F and the high temperature exceeds 75°F only one day in ten. The hottest month of 1970 was July with an average daily high temperature of 69°F.
Relative to the average, the hottest day was January 1. The high temperature that day was 40°F, compared to the average of -9°F, a difference of 48°F. In relative terms the warmest month was March, with an average high temperature of 32°F, compared to an typical value of 19°F.
The longest warm spell was from October 28 to November 16, constituting 20 consecutive days with warmer than average high temperatures. The month of March had the largest fraction of warmer than average days with 84% days with higher than average high temperatures.
The coldest day of 1970 was December 31, with a low temperature of -48°F. For reference, on that day the average low temperature is -21°F and the low temperature drops below -38°F only one day in ten. The coldest month of 1970 was January with an average daily low temperature of -25°F.
Relative to the average, the coldest day was December 3. The low temperature that day was -46°F, compared to the average of -5°F, a difference of 41°F. In relative terms the coldest month was December, with an average low temperature of -21°F, compared to an typical value of -13°F.
The longest cold spell was from November 29 to December 16, constituting 18 consecutive days with cooler than average low temperatures. The month of June had the largest fraction of cooler than average days with 77% days with lower than average low temperatures.
The longest freezing spell was from January 2 to February 22, constituting 52 consecutive days with temperatures strictly below freezing.
The clearest month of 1970 was January, with 58% of days being more clear than cloudy. The longest spell of clear weather was from November 29 to December 9, constituting 11 consecutive days that were clearer than they were cloudy.
The cloudiest month of 1970 was June, with 90% of days being more cloudy than clear. The longest spell of cloudy weather was from June 7 to July 20, constituting 44 consecutive days that were cloudier than they were clear.
This station provides hourly reports of significant weather events at and around the station, but does not report the quantity of precipitation at the station itself. This is common for weather stations located outside of the United States, and for a small subset of stations in the United States that are located at lesser used and smaller airports.
This station reports when significant weather events (including precipitation) are visually observed at or near the station. Such events do not always correspond to measured quantities of liquid equivalent precipitation, such as when the event is near by not at the station, or in the case of solid precipitation that does not melt in the collection basin.
The day in 1970 with the most precipitation observations was April 24. There were 24 hourly weather reports that day (out of a maximum of 24) in which some form of precipitation was observated at or near the station. The month with the most precipitation observations was October, with 288 hourly present weather reports involving some form of precipitation.
As determined by the present weather reports, the longest dry spell was from January 3 to January 17, constituting 15 consecutive days with no observed precipitation. The month with the largest fraction of days without observed precipitation was January, with 65% of days reporting no observed precipitation at all.
The month with the largest fraction of days with at least some observed precipitation was October, with 77% of days reporting some observed precipitation.
In this section we consider only those weather reports that indicate liquid precipitation. For the purposes of this analysis, we include thunderstorms even though some thunderstorms are not accompanied by liquid precipitation.
The month of 1970 with the largest number of those reports was August, with a total of 97 reports. The day with the largest number of those reports was June 22, with a total of 17 reports.
This station reports when snow is observed falling but does not report the quantity of snow that has fallen or the depth of snow on the ground.
In this section we consider hourly weather reports that contain an observation of falling snow. These reports do not necessarily correspond to accumulation.
The first reported snow fall in 1970 was on September 7; the last was on May 7. The month of 1970 with the largest number of those reports was October, with a total of 269 reports. The day with the largest number of those reports was April 24, with a total of 24 reports.
Humidity is an important factor in determining how weather conditions feel to a person experiencing them. Hot and humid days feel even hotter than hot and dry days because the high level of water content in humid air discourages the evaporation of sweat from a person's skin.
When reading the graph below, keep in mind that the hottest part of the day tends to be the least humid, so the daily low (brown) traces are more relevant for understanding daytime comfort than the daily high (blue) traces, which typically occur during the night. Applying that observation, the least humid month of 1970 was May with an average daily low humidity of 29%, and the most humid month was November with an average daily low humidity of 70%.
But it is important to keep in mind that humidity does not tell the whole picture and the dew point is often a better measure of how comfortable a person will find a given set of weather conditions. Please see the next section for continued discussion of this point.
Dew point is the temperature below which water vapor will condense into liquid water. It is therefore also related to the rate of evaporation of liquid water. Since the evaporation of sweat is an important cooling mechanism for the human body, the dew point is an important measurement for understanding how dry, comfortable, or humid a given set of weather conditions will feel.
Generally speaking, dew points below 50°F will feel a bit dry to some people, but comfortable to people accustomed to dry conditions; dew points from 50°F to 68°F are fairly comfortable to most people, and dew points above 68°F are increasingly uncomfortable, becoming oppressive around 77°F.
To take some examples, and basing our categorization on the daily high dew point in 1970, January had 31 dry days, no comfortable days, and no humid days; April had 30 dry days, no comfortable days, and no humid days; July had 22 dry days, 9 comfortable days, and no humid days; and October had 31 dry days, no comfortable days, and no humid days.
The highest sustained wind speed was 28 mph, occurring on June 25; the highest daily mean wind speed was 15 mph (May 14); and the highest wind gust speed was 30 mph (June 25).
The windiest month was May, with an average wind speed of 5 mph. The least windy month was December, with an average wind speed of 1 mph.
Visibility is the maximum distance at which a given reference object or light can be clearly discerned. In the United States, visibilities that are greater than or equal to 10 miles are typically reported as 10 miles.
The day of 1970 with the lowest average visibility was December 4, with an average visibility of 0.4 mi. The month with the lowest average visibility was December, with an average visibility of 8.9 mi. With an average visibility of 26.4 mi, the month of May had the highest average visibility.
The cloud ceiling is the altitude of the lowest layer of clouds that are at categorized as broken (mostly cloudy) or overcast (cloudy). If no such cloud layer exists then the ceiling is unlimited and no value is reported.
The day of 1970 with the lowest average cloud ceiling was January 30, with an average cloud ceiling of 197'. The month with the lowest average cloud ceiling was January, with an average cloud ceiling of 5313'. The month of May has the highest average cloud ceiling, with an average cloud ceiling of 9212'.