Weather and Climate
Summary and Forecast
August 2026 Report
Gregory V. Jones, Ph.D.
August 3, 2026
Summary:
- Near average to cooler than average* July along the West Coast, with much warmer than average conditions inland across the rest of the West.
- Precipitation amounts were mixed across the West, with seasonally dry conditions in most of the PNW and California, while monsoon flow brought rain to the Great Basin, Southwest, and much of the Rockies.
- Not much change in the drought footprint from last month, with roughly 90% of the western US in some level of drought and nearly 50% in more extreme drought. Forecasts are still pointing to reduced drought conditions in the Southwest, Great Basin, and southern Rockies due to continued monsoon flow.
- For the next few days to a week or so, a high pressure heat dome will build over the West with extreme heat for most regions. Some relief is possible next week, but the heat dome is expected to build back by mid-month.
- The August outlook has the majority of the lower 48 states likely to experience a warmer than average month, while precipitation is forecast to be below average in the PNW and higher than normal in the Southwest and Great Basin due to conditions that will likely support continued monsoon flow.
- Heading into ripening and harvest, the seasonal forecast for the western US also continues to call for warm and mostly dry. Pacific Ocean SST and atmospheric observations indicate that El Niño conditions continue to intensify, suggesting the event is evolving toward a very strong El Niño. While the effects of this event will play out more over the fall and winter, one of the more likely impacts is a stronger sub-tropical jet stream, which in turn would support a more active monsoon as we head into fall.
*Note that all references to normal or averages in this report are to the 1991-2020 climate normal for each weather/climate parameter unless stated otherwise. See this website for more information on climate normals.
For a PDF of this report, click here.
Past Month and Year to Date:
The broad circulation pattern over the Pacific and North America resulted in a relatively cool West Coast during July. High pressure has been shifted more easterly toward the middle of the country while the Pacific high pressure has been parked further west over the Pacific, leaving a trough of low pressure in the Gulf of Alaska influencing the western states. The result for July was very warm conditions over the Rockies (3-8 degrees) and near average temperatures for the coastal states (-1 to +1 degrees) (Figure 1). The rest of the country was generally warmer than average in July (1-2 degrees), except for portions of Texas and far eastern New England where cooler temperatures came from consistent cloud cover and precipitation during the month (not shown).
Western US precipitation during July was dominated by two scenarios: 1) seasonally dry conditions for much of the PNW and California, and 2) monsoon flow that brought 130-300 percent of normal for the month over much of the Southwest, Great Basin, and Rockies (Figure 1). Portions of western Washington and northwest Oregon received some precipitation during the month but still tended dry overall. Significant precipitation came to Northern Nevada and southeastern Oregon via thunderstorms, leading to 300 percent or more above normal in some areas, but also numerous wildfires. Mixed precipitation amounts across the rest of the country in July, with much of the Plains, Southeast, and Great Lakes drier than average, while storms in Iowa, the mid-South, and New England, along with a tropical system in Louisiana and Texas, brought those areas 150-300% of normal precipitation for the month (not shown).
Figure 1 – Western US July 2026 temperature departure from normal (left) and percent of normal precipitation (right; images from WestWide Drought Tracker, Western Region Climate Center; University of Idaho).
Year to date temperatures continue to run warmer than average across the western US (Figure 2). The warmest regions have been the southwest, portions of the Great Basin, and most of the Rockies, with temperatures 4-8 degrees warmer than average. California has been warm as well, with temperatures 2-4 degrees above average, while western Oregon and Washington have experienced a cooler January through July period with temperatures closer to 0.5-2 degrees above average. The majority of the rest of the country has seen warmer-than-average temperatures since the first of the year, running 2-4 degrees above average from Texas and the Mississippi River Valley to the Great Lakes. At the same time, the Southeast and eastern seaboard have experienced closer to average or slightly cooler year to date conditions (not shown).
Precipitation amounts over the western US through July have remained mostly drier than normal (Figure 2), although isolated areas in northwestern Nevada and southcentral Oregon, the northern Rockies, southern Arizona, and New Mexico have been wetter than normal, most of which is due to an active monsoon flow this summer. The January through July period has also seen drier than average conditions in the central to northern Plains, the southeast, and Florida (not shown), while portions of Texas, the Gulf Coast, the Ohio River valley, and the Great Lakes have experienced roughly 150-250% of average precipitation, helping to alleviate drought concerns in those regions (see Drought section).
Figure 2 – Western US year to date (January through July 2026) temperature departure from normal (left) and percent of normal precipitation (right; images from WestWide Drought Tracker, Western Region Climate Center; University of Idaho).
Heat Accumulation:
Moving past mid-vintage, growing degree-days (GDDs) over the western US continue to show above average amounts (Figure 3). California and the southwest are running 300 or more GDD above average, while portions of the PNW are closer to average or running 100-300 GDD above average. Like this vintage’s phenological timing, which is early across most wine regions in the West, GDD accumulation is also running ahead of normal, with as much as 20-30 days ahead of normal in California and the Southwest and between 10-20 days ahead in the PNW (not shown).
Four stations in the main wine regions in Oregon are showing above average GDD values at the end of July 2026. These four locations are 15-33% and 2-21% above average compared to the 1981-2010 and 1991-2020 climate normals, respectively. Lower maximum temperatures have reduced accumulation somewhat over the last few weeks in these locations, dropping them to below the same period in 2025 (-5% Medford; -6% Roseburg; -2% Milton-Freewater) or slightly ahead in McMinnville (+4%).
Figure 3 – Western US March through July 2026 growing degree-days (image from Climate Impacts Research Consortium, University of Idaho).
Figure 4 – Cumulative growing degree-days (base 50°F, no upper cut-off) for McMinnville, Roseburg, Milton-Freewater, and Medford, Oregon. Comparisons between the current year (2026) and a recent cool year (2010), a recent warm year (2015), and both the 1981-2010 and 1991-2020 climate normals are shown (NCDC preliminary daily data).
Drought Watch:
Heat over the western US and into the Plains increased drought levels, while rains across the south and into the Ohio River valley lowered drought concerns there (Figure 5). For the lower 48 states, the overall drought footprint remained just under 70%, with the most extreme drought categories also dropping to just above 28%. Continued warm and dry conditions over most of the western US during July kept the drought footprint at close to 90%, with the most extreme categories dropping slightly to just under 49% of the west. A dry but mild summer has kept California at just over 65% in drought, with less than 1% of the state in the more extreme categories of drought at month’s end. A very dry month in Oregon increased its drought footprint slightly to close to 99% of the state, with the extreme drought categories (severe, extreme, and exceptional) rising to nearly 58% now. Only a small portion of western Washington received precipitation in July, resulting in drought concerns rising in the state to nearly 90% in drought, with the most extreme categories of drought remaining at 8%. The southern portions of Idaho and Montana received some welcome monsoon rains during July, lowering drought concerns for some areas of the states. Montana saw a drop in the overall drought footprint to nearly 76%, with the extreme categories dropping to less than 16% of the state. Idaho’s overall drought footprint dropped 10% from last month and is now at close to 89%; however, the most extreme drought categories remained over 53% of the state (Figure 5).
The pattern in the seasonal drought outlook (Figure 5; right panel) is much the same as last month. Monsoon flow is forecast to improve or remove drought declarations in the Southwest, Four Corners, and portions of the Great Basin, although this could be very scattered over the region. A wet couple of months has brought improvement in the drought situation for the Gulf Coast states and the Southeast, along with the Piedmont and Appalachian Mountains into the mid-Atlantic. Much of the Great Plains across to the western Great Lakes states and south into northern portions of Texas are forecast to remain in drought or see drought develop further. For the West Coast states, northern California, most of Oregon, Washington, and western Idaho are likely to see drought conditions develop further as we close the summer dry season (Figure 5; right panel).
Figure 5 – Current US Drought Monitor and seasonal drought outlook.
ENSO Watch :
El Niño conditions are strengthening across the tropical Pacific, with sea surface temperature (SST) anomalies in the main El Niño region showing a steady upward trend (Figure 6). Tropical Pacific atmospheric conditions continue to develop that are consistent with El Niño. Together, these Pacific Ocean SST and atmospheric observations indicate that El Niño conditions continue to intensify, suggesting the event is evolving toward a very strong El Niño. The Climate Prediction Center (CPC) continues with an El Niño Advisory in its alert system. Models of the ocean and atmosphere from numerous agencies around the world continue to show El Niño conditions strengthening into the Northern Hemisphere fall and winter (100% chance) with a 97% chance that it will persist through early spring of 2027. I want to continually remind everyone that it is important to note that stronger El Niño events do not guarantee strong impacts; they can only make certain aspects of regional effects more likely. A stronger sub-tropical jet stream is one of the more likely effects, which in turn would support a more active monsoon as the seasonal outlooks keep leaning towards in the 90 day forecast.
Figure 6 – Global sea surface temperatures (°C) for the period ending August 1, 2026 (image from Tropicaltibits.com).
North Pacific Watch:
The majority of the North Pacific remains warmer than average, with a major change to note over the last month. First, the horseshoe-shaped area of cooler SSTs from the Gulf of Alaska along the coast of western North America and southward to Hawaii has warmed (Figure 6). This pattern is common during the negative phase of the Pacific Decadal Oscillation, and warming would indicate that the North and Tropical Pacific may become ‘in phase’, which would bring more likely impacts over North America. This will be very important to watch over the transition into fall and winter.
Forecast Periods:
Next 5 Days: A large high pressure area has moved over the western US with sinking air creating a significant heat dome. Very warm temperatures over most of the West for the next few days. With the Pacific High further west than normal, a trough has been in place just off British Columbia. The trough is bringing northwest flow, which will keep the heat from pushing too far north, but it will still be warm for pretty much the entire West during the next few days. No precipitation in sight, other than some isolated monsoon-related showers in the Southwest and Four Corners area.
6-10 Day (valid August 8-12): Current forecasts have the entire US likely to experience above average temperatures into the second week of the month. The low pressure area off British Columbia is likely to remain in place, bringing westerly flow off the Pacific and slightly cooler air across the northern tier of states, but it is still likely to be warmer than average. The warmest area of the country will likely be the Great Basin across the Rockies into the central Plains and eastward to the mid-Atlantic. Below average precipitation is likely in the PNW, while monsoon flow will increase chances for precipitation in the Southwest. Near normal precipitation is likely in the south and above average likely in the Great Lakes region.
8-14 Day (valid August 10-16): The entire country, including Alaska and Hawaii, is likely to see above average temperatures into mid-month. Only northern New England is likely to be closer to normal. In terms of precipitation, forecast models are still pointing to a relatively strong monsoon bringing above average chances for the Southwest and into the Great Basin. From Texas across to the Southeast, conditions will likely remain on the dry side or near normal, while the Great Lakes and Ohio River valley are forecast to see above average precipitation.
30 Day (valid August 1-31): The August temperature outlook has the majority of the lower 48 states expected to experience a warmer than average month (Figure 7). The highest forecast confidence for above-normal temperatures is given for coastal California and Texas into Oklahoma, Arkansas, and Louisiana. Equal chances of below, near, or above-normal temperatures are forecast for the northern Plains, the Great Lakes region, and New England, where a more variable temperature pattern is expected in August. The August precipitation outlook has much of the country with equal chances of seeing above, average, or below normal amounts (Figure 7). The northwestern PNW and much of Texas, Oklahoma, Arkansas, and Louisiana are forecast for below normal precipitation. A wetter than average month is most likely in portions of the southwest, where an active monsoon flow is likely to continue in August. The only region in the eastern US that is forecast for above normal precipitation for the month is northern New England (Figure 7).
90 Day (valid August-September-October): The late summer into fall forecast continues to tilt toward much of the country seeing above average temperatures (Figure 7). The highest forecast confidence for above-normal temperatures over the next three months is centered over the PNW, south Texas, and the Southeast, with decent chances of warmer than average temperatures across the West, South, and Eastern seaboard. Equal chances of below, near, or above-normal temperatures are forecast for the Midwest and Great Lakes, where a more variable temperature pattern is expected over the next 90 days. The 90 day precipitation forecast is largely pointing to equal chances of below average, near, or above average over most of the US; however, there is high confidence in below average amounts likely in northwest Washington and the western Great Lakes, while monsoon flow is forecast to continue in the Southwest (Figure 7).
Figure 7 – Temperature (left panel) and precipitation (right panel) outlooks for the month of August (top panel) and August, September, and October (bottom panel) (Climate Prediction Center, climate.gov).