Late March at White Sands Missile Range is characterized by abundant sunshine and dry west-to-southwesterly winds.
Marchers can expect warm, windy, and dry conditions. In fact, March is the driest month of the year, in terms of average precipitation, with only 0.30″. Long dry spells are common. Not surprisingly, snow and thunderstorms are rare.
The main weather hazard in late March is the threat of driving windstorms, which can produce areas of blowing dust and sand, due to the typically dry soil conditions.
Over the period of record 1980-2004, the 24-hour average wind speed in late March is about 8 mph, with daily maximum gusts of near 30 mph. However, wind speeds along the east-facing slopes of the Organ and San Andres Mountains, near much of the march route, can be much higher, with gusts of 50-60 mph quite common during windstorms. This is due to the downsloping effect. Such gusts greeted many of those crossing the finish line during the 2018 event.
Winds are typically at their calmest early in the morning, around sunrise, then gradually increase in intensity as the ground heats up through the morning. Peak winds are usually observed during the mid or late afternoon hours.
Morning low temperatures average in the low-mid 40’s Fahrenheit, with subfreezing temperatures unlikely. Ironically, a windy night will actually keep morning temperatures higher, with low-mid 50’s common in such cases.
Temperatures rise fairly quickly in the late March New Mexico sun, reaching the mid-60’s by noon and topping out in the mid-70’s around 4pm. Exceptionally warm days may reach the mid-80’s. Relative humidities are low, as might be expected in desert environment, and in late March average 52% at 5am, 18% at 11am, 18% at 5pm, and 32% at 11pm.