We are now heading into early summer and the snow is quickly melting in the mountains – more quickly in some areas than others. 

This past winter featured record snowfall in California and Utah and above-average snowfall for a larger portion of the west, including the Central/Southern Rockies and Oregon Cascades.

By April 1st, snowpack was right around average in the Washington Cascades and below average across far Northern Idaho/Montana and Western Canada.

May Recap:

Cold and snowy conditions persisted across a large portion of the West through much of April before turning milder late in the month. During May, most areas saw a quick flip to above-average warmth and accelerated snowmelt, except for California where near-average temperatures have led to a more gradual snowmelt, and thankfully, limited flooding issues.

Temperatures were above average across the Central Rockies, but well above average across northernmost portions of the Western U.S. as well as Western Canada where many areas experienced record high temperatures. 

Unusually hot temperatures in the north resulted in a devastating outbreak of wildfires in Northern Alberta, which produced smoke that briefly impacted portions of the U.S. during late May.

Contrary to popular belief, May is actually peak wildfire season east of the Continental Divide in Central/Northern Alberta before wetter conditions (typically) arrive in the summer. But wildfire activity this May was much more severe than usual.

In terms of moisture, precipitation compared to average was highly variable across the Western U.S. given the hit-or-miss nature of showers and thunderstorms. Most areas did not see significant deviations from average, except for the Cascades of WA/OR and also Western Canada where widespread drier-than-average conditions were experienced.

Also, the Front Range and adjacent plains of Colorado experienced a very wet May – one of the wettest on record in some areas. 

Current Snowpack Update:

Heading into early June, snowpack remains well above average across the Sierra Nevada Range. Snowmelt rates were significant in Utah in May due to warm temperatures, but snowpack is still well above average, which speaks to just how much snow added up this winter.

Snowpack has decreased rapidly across the Pacific Northwest and Northern Rockies in response to well above-average temperatures in May and a lack of any late-season cold fronts and/or snow events.

Keep in mind that the percent of average snowpack values are exaggerated this late in the year, in both directions, since "average" values are much lower in early June compared to the mid to late winter months. Therefore the snowpack map below should be used just to get a general idea.

Also, the SNOTEL stations where this data come from are typically located below treeline, and don't account for snow conditions that may be experienced in alpine terrain. 

When heading into the mountains early this summer to hike or climb peaks, be sure to check out our Snow Depth Map to get an idea of current snow conditions. The snow depth map is based on model-estimated data, and not first-hand observations. 

Summer Fire Season and Smoke Outlook:

Significant fire activity is tough to predict in advance, because it depends on current weather patterns during the peak summer months just as much as pre-existing climate/moisture conditions. Nevertheless, these pre-existing conditions can still be used to determine regions with higher-than-average or lower-than-average wildfire potential.

The good news is that an exceptional snowpack and a relatively cool and wet spring mean that California is in good shape heading into the summer with below-average fire activity expected. That doesn't mean there won't be any fires, but the odds of significant fires are lower and the best chance of fires will likely hold off until late in the season.

On the other hand, the Washington Cascades, Western Canada, and Northern Idaho/Montana are at risk of having a more severe fire season thanks to a hot and dry spring, as well as earlier than usual snowmelt on the heels of an average to below average winter.

The National Interagency Fire Center has highlighted the Northwest for above-average significant fire potential and California for below-average significant fire potential in July, with similar projections for August and September.

Wildfire smoke conditions are dependent on the size, intensity, and location of wildfires, and just as importantly, the prevailing wind direction. But if and when we see smoky periods this summer across the West, it's more likely to originate from the Northwest and Canada than it is from California.

Also, just because an area is predicted to have above-average wildland fire potential, it's not a guarantee that it will happen. If conditions were to end up cooler or wetter than average in July or August with limited wind events, then fire activity could end up being less than feared.  

June Outlook

The month of June is expected to be warmer than average across the Northwest, which increases the odds of vegetation fuels drying out heading into the peak fire season from July to September.

Cooler-than-average temperatures are expected to prevail across the Southwest in June, where below-average fire potential is expected this month. June is typically peak fire season in the Southwest before monsoon season begins in July.

The last 10 days of May featured slow-moving areas of low pressure moving into the Southwest or West Central U.S., which undercut large ridges of high pressure to the east across the Great Plains and to the north into Western Canada. 

This pattern has favored a consistent feed of subtropical moisture into the Sierra, Great Basin, and Central Northern Rockies where showers and thunderstorms have been a regular occurrence.

This pattern is expected to continue well into June with above-average precipitation expected for a large portion of the West. Some of this moisture may reach the Pacific Northwest as well, though the PNW does better with rainfall when low pressure systems drop in from the Gulf of Alaska, which we have not seen recently.