Thirteen years of Weather Statistics at San Pedro Martir Observatory

TL;DR

This paper provides a comprehensive analysis of thirteen years of weather data from San Pedro Martir Observatory, revealing seasonal patterns and climatological characteristics relevant for astronomical observations.

Contribution

It offers the first long-term, detailed climatological dataset for the observatory, including analysis of temperature, humidity, wind, and precipitation over 13 years.

Findings

Median daytime temperature 10.3°C, nighttime 7.0°C

Relative humidity peaks in July-September

Annual precipitation averages 313 mm

Abstract

We present weather statistics for thirteen years of data gathered with the meteorological stations at Observatorio Astron\'omico Nacional in the Sierra San Pedro M\'artir (OAN-SPM) over the period 2007-2019. These weather stations include sensors that measure temperature, atmospheric pressure, relative humidity, precipitation and wind conditions, among other climatological variables. The median values of the air temperature are $10.3^{\circ}$ C and $7.0^{\circ}$ C for daytime and nighttime, respectively. The relative humidity follows a seasonal variation with April-June being the driest months while July-September being the most humid. The median values for the sustained wind speed are 11 and 14 km hr$^{-1}$ for daytime and nighttime data, respectively. Preferred wind directions are SSW and North. Sustained winds are stronger at night and during December, January and February. Our data indicate an annual mean rain precipitation of 313 mm, most of which occurs during the summer season as afternoon thunderstorms.