Temperatures in White Mountains in late March typically range from the 20's to lower 30s during the day to zero to 10 above at night. The sun is high in the sky this time of year and, as a result, temperatures sometimes vary by more than 30 degrees between day and night. Due to the hilly terrain, strong temperatures inversions frequently exist (especially at night) and it would not be uncommon to dive into a valley bottom (like when you cross Beaver Creek) where the mercury plummets 20 degrees or more over a very short distance. For climate buffs, record high temperatures in the 50's have occurred at the end of March, but record low readings approaching 40 below zero have also been observed (data is from Fairbanks).
The prevailing wind in the White Mountains is from the northeast. This is no guarantee that the wind will be blowing from this direction. But a light northeast breeze is often present over the higher terrain and in exposed areas. Valley bottoms tend to have less wind but this is not the case everywhere. Strong, gusty winds along with areas of drifting and blowing snow are not out of the question even in late March.
March is the 2nd driest month of the year in the White Mountains, just after April. Snowfall tends to taper off during the later part of the winter. Average snowfall in Fairbanks for the entire month of March is around 5 inches, and will be slightly more in the White Mountains. Be aware that many feet of snow have fallen in March and then there have been some years with no new snow.
All of this being said, March is still winter and temperatures below zero are still possible. Winds can blow from any direction and heavy snow can blanket the trail. Racers should be prepared for a wide range of conditions and pack accordingly.
But don't let the extreme climate statistics and potentially bad weather frighten you. March is most notably a beautiful time of the year when the days are long, the sun is warm, and the trail conditions are at their prime!
Current weather conditions at the race start/finish: Wickersham Dome trailhead weather
Fairbanks Area Forecasts: National Weather Service
The days are have grown noticeably longer in interior Alaska by late March, as well as the angle of the sun in the southern sky. There is "usable" twilight late into the evening. There are typically about 1.5 hours of bright twilight on either side of sunrise and sunset. Although this will be less if there is cloud cover. The table below lists daylight as well as twilight information for the White Mountains for March 30, 2014.
Sun and Moon Information
Begin Civil Twilight 06:24 ADT
Sunrise 07:14 ADT
Sunset 20:38 ADT
End Civil Twilight 21:30 ADT
Moon phase on 30 March: new Moon