Storm and Extreme Weather Activity:
Cold fronts generally come from the W and NW, and often bring wind and rain to the area. Warm fronts approach from the ESE or SE direction, bringing secondary winds.

Thunderstorms are not frequent, as indicated above, but do occur November through April. They typically occur in the late afternoon and pass relatively quickly (within 3 hours). Also occurring November through April are low hanging clouds of fog in the evening to mid-morning. These clouds result in poor visibility conditions during this period of the day for aircraft and traffic in the mountains.
The region very rarely experiences extremely high or low temperatures. For this reason, average snowfall is zero and days of freezing are virtually limited to a week in January.

This region suffers low rainfall averages, so droughts are common. The river brings in snow melt from the neighboring mountains, and underground springs provide much of the aquifer water supply. On average, droughts occur over eight years of any 30-year period. The last reported drought spanned from 1987 to 1990, with high risk for drought until April of 1993, when water supplies fully recovered.

Earthquake activity is extremely common in the area, much like the entire state of California. The Rinconada and San Andreas fault zones are to the east and west of the land site. In the vicinity of Keene, approximately 100 earthquakes occur each month, with the average magnitude of 1.6 at its epicenter. Of these earthquakes, only one is of a significant magnitude (3 or higher) at its epicenter. The vast majority of these earthquakes do not result in damage to structures or buildings. Approximately once every four years, an earthquake is felt with a magnitude above 3.5 at Keene (as opposed to its epicenter), and may cause structural damage. None of these major earthquakes has occurred within 50 miles of Keene, in the last 100 years.

Rotor Winds high in the mountains north of Keene may be a hazard to approaching or departing aircraft. These can create unpredictable downdrafts and dangerous turbulence. It is advisable to direct airplanes away from these regions during take-off or landing. Airplanes should be safe from these winds during cruising altitude.