Last updated: August 26, 2025
Article
Climate and Water Monitoring at Capulin Volcano National Monument: Water Year 2024
NPS/MELISSA WEIH
Overview
Together, climate and hydrology shape ecosystems and the services they provide, particularly in arid and semi-arid ecosystems and across the Southern Plains (Woodhouse and Overpeck 1998). Understanding changes in climate, groundwater, and surface water is key to assessing the condition of park natural resources—and often, cultural resources.
At Capulin Volcano National Monument (Figure 1), Southern Plains Inventory and Monitoring Network scientists study how ecosystems may be changing by taking measurements of key resources, or “vital signs,” year after year—much as a doctor keeps track of a patient’s vital signs. This long-term ecological monitoring provides early warning of potential problems, allowing managers to mitigate them before they become worse. At Capulin Volcano National Monument, we monitor climate and groundwater, among other vital signs.
Groundwater conditions are closely related to climate conditions. Because they are better understood together, we report on climate in conjunction with water resources. Reporting is by water year (WY), which begins in October of the previous calendar year and goes through September of the water year (e.g., WY2024 runs from October 2023 through September 2024). This web report presents the results of climate and groundwater monitoring at Capulin Volcano National Monument in WY2024.
Reference: Woodhouse, C. A., and J. T. Overpeck. 1998. 2000 years of drought variability in the central United States. Bulletin of the American Meteorological Society 79(12): 2693–2714. https://doi.org/10.1175/1520-0477(1998)079%3C2693:YODVIT%3E2.0.CO;2
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Climate and Weather
There is often confusion over the terms “weather” and “climate.” In short, weather describes instantaneous meteorological conditions (e.g., it’s currently raining or snowing, it’s a hot or frigid day), and climate reflects patterns of weather at a given place over longer periods of time (seasons to years). Climate is the primary driver of ecological processes on earth. Climate and weather information provide context for understanding the status or condition of other park resources.
Methods
A National Oceanic and Atmospheric Administration Cooperative Observer Program (NOAA COOP) weather station (Capulin NM #291450) is located 2.9 miles (4.7 km) south of Capulin Volcano National Monument and has been operational since 1995 (Figure 1). This station typically provides a reliable climate dataset. However, in WY2024 it was missing data on 75 days. As a substitute, climate analyses in this report use WY2024 and 30-year averages (1991–2020) of gridded surface meteorological (GRIDMET) data from the location of the station. Subsequent reports may revert to the weather station as the data source, depending on future data quality.
GRIDMET is a spatial climate dataset at a 4-kilometer resolution that is interpolated using weather station data, topography, and other observational and modeled land surface data. Temperature and precipitation estimated from GRIDMET may vary from actual weather at a particular location depending on the availability of weather station data and the difference in elevation between the location of interest and that assigned to a grid cell. Data from both the weather station and GRIDMET are accessible through Climate Analyzer.
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Results
Precipitation
Annual precipitation at Capulin Volcano National Monument in WY2024 was 15.00″ (38.1 cm), 2.27″ (5.8 cm) less than the 1991–2020 annual average. Overall, the cool season (October–March) received 4.86″ (12.3 cm), 0.93″ (2.4 cm) more than the 1991–2020 average (Figure 2). Only November received substantially less precipitation than average. Precipitation in the other cool season months was similar to average or up to 2.5 times the long-term average. The warm season (April–September) was drier than average, receiving 10.13″ (25.7 cm) of precipitation, 3.21″ (8.2 cm) less than average. The largest precipitation deficits primarily occurred in April, July, and August. Precipitation totals during the other three warm season months were similar to average.
Air Temperature
The mean annual maximum temperature at Capulin Volcano National Monument in WY2024 was 65.0°F (18.3°C), 0.9°F (0.5°C) above the 1991–2020 average. The mean annual minimum temperature in WY2024 was 35.5°F (1.9°C), 1.2°F (0.6°C) above the 1991–2020 average. Mean monthly maximum and minimum temperatures in WY2024 differed by as much as 5.1°F (2.9°C; see June as an example) relative to the 1991–2020 monthly averages (Figure 2). Mean monthly maximum and minimum temperatures were above or similar to average in all months except January and March.
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Drought
Reconnaissance drought index (Tsakiris and Vangelis 2005) provides a measure of drought severity and extent relative to the long-term climate. It is based on the ratio of average precipitation to average potential evapotranspiration (the amount of water loss that would occur from evaporation and plant transpiration if the water supply was unlimited) over short periods of time (seasons to years). The reconnaissance drought index for Capulin Volcano National Monument indicates that WY2024 was drier than the 1991–2024 average from the perspective of both precipitation and potential evapotranspiration (Figure 3).
Reference: Tsakiris G., and H. Vangelis. 2005. Establishing a drought index incorporating evapotranspiration. European Water 9: 3–11.
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Groundwater
Groundwater is one of the most critical natural resources of the Southern Plains and American Southwest. It provides drinking water, irrigates crops, and sustains rivers, streams, and springs throughout the region.
Methods
Capulin Volcano National Monument groundwater is monitored at one well, the park’s water supply well (well NM-26614; Figure 1). The New Mexico Bureau of Geology and Mineral Resources began monitoring the well in 2022 using manual methods. In water years 2014–2017, the Southern Plains Network monitored the well using automated methods. Both datasets are available at the Healy Collaborative Groundwater Monitoring Network.
Results
Groundwater level was 647.05 feet below ground surface (ft bgs; 197.22 m) on 9 May 2024, slightly below the groundwater level in the previous year (Table 1). Regular well pumping causes the water level to drawdown approximately 0.6 ft (0.2 m). The monitoring data indicate that water level is slowly declining in the well (Figure 4), although additional data are needed to rigorously evaluate trends.
Table 1. Groundwater monitoring results in water year (WY) 2024, Capulin Volcano National Monument (amsl = above mean sea level; bgs = below ground surface).
| State Well Number | Location | Wellhead Elevation (ft amsl) |
Mean Depth to Water (ft bgs) |
Mean Water Level Elevation (ft amsl) |
Change in Elevation from WY2023 (± ft) |
Change in Elevation from Earliest Recorded Water Level (± ft and year of first record) |
|---|---|---|---|---|---|---|
| NM-26614 | Capulin Volcano National Monument | 7,272.00 | 647.05 | 6,624.95 | −0.42 | −12.65 (1962) |
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Report Citation
Authors: Kara Raymond, Andy Ray
Raymond, K., and A. Ray. 2025. Climate and Water Monitoring at Capulin Volcano National Monument: Water Year 2024. Southern Plains Network, National Park Service, Pecos, New Mexico.