April 2026 snow summary
- Snow-covered area across the western United States was 41 percent of average for April, ranking last in the 26-year satellite record.
- Snow albedo, also known as snow brightness, moderated by snow age and dust, declined throughout the month and remained below the twenty-fifth percentile.
- Snow cover duration was 34 percent of average at the end of the month.
- Snow water equivalent (SWE) remained well below average in most states during April.
Overview of conditions
Snow-covered area in April across the western United States was 41 percent of average, at 118,00 square kilometers (46,000 square miles) of snow cover, ranking last in the 26-year satellite record (Table 1). Snow-covered area for April was 510,000 square kilometers (197,000 square miles) below 2023, the highest year, and 15,000 square kilometers (6,000 square miles) below 2015, the second lowest April on record.
Table 1. April 2026 Snow Cover in the Western United States (Relative to the 26-Year Satellite Record)
| Snow-Covered Area | Square Kilometers | Square Miles | Rank |
|---|---|---|---|
April 2026, Lowest | 118,000 | 46,000 | 26 |
2001 to 2025, Average | 287,000 | 111,000 | -- |
2023 Highest | 628,000 | 242,000 | 1 |
2025, Last year | 235,000 | 91,000 | 21 |
2015, Previous lowest | 133,000 | 51,000 | 25 |
Snow cover was far below average in all western states in April (Figure 1, left). Only Idaho (53 percent of average) and Washington (52 percent of average) had snow-covered area above 50 percent of average. Wyoming had the next highest snow cover relative to average at 49 percent. Montana and California followed at 46 and 40 percent of average, respectively. The situation in Colorado, Utah, and Oregon was dire, with 27, 25, and 23 percent of average snow cover, respectively. Conditions were even worse in Nevada at 13 percent of average and New Mexico at 11 percent of average. Almost no snow was observed in both Arizona and South Dakota. Almost all western states during April except Arizona and South Dakota had an increase in snow cover relative to average compared to March.
All HUC2 basins in the western US also experienced below average snow cover during April (Figure 2, right). As in March, the Pacific Northwest (61 percent of average) and Missouri (39 percent of average) had the highest snow cover relative to average. The California basin was a close third, at 38 percent of average, followed by the Upper Colorado at 29 percent. The Great Basin (25 percent of average), Rio Grande (24 percent of average), and Arkansas-White-Red (23 percent of average) all had around a quarter of average snow cover and almost no snow was present in the Lower Colorado river basin.
Conditions in context: Snow cover
Snow cover was very low in April but did not substantially decrease over the month (Figure 2, upper left): extent started at 129,000 square kilometers (50,000 square miles) and ended at 114,000 square kilometers (44,000 square miles). Across most mountainous areas, snow cover was 0 to 20 percent below average at high elevations and further below average at lower elevations. This was particularly noticeable in Colorado, Utah, and Wyoming, where snow cover was 80 to 100 percent below average in most low elevation areas surrounding mountain ranges. Areas with above average snow cover were limited to parts of central Idaho and the northern Cascades in Washington.
Snow cover duration, measured in days summed from October 1, 2025, to April 30, 2026, continued to increase throughout April but remained only 34 percent of average (Figure 2, bottom right). Snow cover duration was well below average in all western states. In large areas of Colorado, Wyoming, Idaho, Utah, and Oregon, snow cover duration was 60 to 120 days below average, with some areas experiencing close to 150 fewer snow-covered days than average (Figure 2, lower right). California, Arizona, and New Mexico had closer to average number of snow-covered days for the year, but snow cover duration was still 10 to 60 days below average in most mountainous regions.
Average snow brightness, known as snow albedo, steadily declined and remained below average throughout the month (Figure 3, left). On April 1, average albedo values were 54 percent and decreased to 49 percent by the end of the month. Albedo remained below the twenty-fifth percentile for the entire month.
Snow albedo was also below average (Figure 3, right). In the mountainous regions of Colorado, Utah, Wyoming, and the southern Sierra Nevada in California, the snow was extremely dark with snow albedo values between 20 and 25 percent below average. Snow albedos for Washington, Oregon, northern California, and Montana were closer to average. In Nevada, Arizona, and New Mexico, hardly any snow was present.
Conditions in context: Snow water equivalent (SWE)
Snow water equivalent (SWE) was well below average in most areas at the beginning of April (Figure 4, left). In California, Oregon, Nevada, Utah, Colorado, Arizona, and New Mexico, SWE values ranged between 0 and 45 percent of average. Farther north, however, SWE was above average in some areas of Montana and northwest Wyoming. Some stations in Idaho and northern Washington were also above average. Conditions remained relatively constant throughout the month (Figure 4, right).
Although SWE remained below average at most stations during April, absolute SWE did increase at many sites during the month (Figure 5, left). California and Montana had the largest individual increases, with some stations gaining more than 25 centimeters (10 inches) of SWE during the month. However, both states experienced no net change in SWE when averaged across all stations (Figure 5, right). This was the case in most western states during April with overall average changes near zero. Only Washington experienced a significant average decrease in SWE during the month at roughly 10 centimeters (4 inches). Washington also saw the largest losses at individual stations; SWE declined by over 30 centimeters (12 inches) at some stations in April.
