Monthly average temperatures were 1 to 3 °F above the 1991-2020 normal for much of Arizona (light-orange and orange areas on map). Several locations in the central and south-central parts of the state recorded near-normal temperatures (white areas on map). For reference, monthly average temperatures in September 2025 were within 2 °F of normal for most of the state.

Area-average maximum and minimum temperatures during September 2026 were 82.9 and 60.2 °F for the Sonoita AVA, 89.6 and 63.4 °F for the Verde Valley AVA, and 86.8 and 62.1 °F for the Willcox AVA. Respective September normals are 83.9 and 57.0 °F, 90.4 and 58.4 °F, and 87.8 and 58.3 °F.

Temperature last month ranged between 95.5 and 53.6 °F at the AZMet Bonita station, 91.9 and 50.4 °F at the AZMet Elgin station, and 98.4 and 53.6 °F at the AZMet Willcox Bench station.

Due in large part to moisture from hurricane Polo, monthly precipitation totals were more than 250 % of normal for swaths across southern and eastern parts of the state (dark-blue areas on map). Elsewhere, amounts largely were 125 to 200 % above normal (light-aqua, aqua, and dark-aqua areas on map). A few locations in north-central Arizona recorded near-normal totals (white areas on map). Precipitation during September 2025 was more than 125 % of normal for many extreme-western, central, east-central, and southeastern parts of the state. Many locations in south-central and north-central Arizona recorded near-normal totals, with some along the northern state border recording below-normal amounts.

Area-average precipitation totals in September 2026 were 4.36 inches for the Sonoita AVA, 3.12 inches for the Verde Valley AVA, and 3.09 inches for the Willcox AVA. Respective September normals are 1.95, 1.53, and 1.40 inches.

Total precipitation last month was 3.33, 1.84, and 3.65 inches at the AZMet Bonita, Elgin, and Willcox Bench stations, respectively.

Dig further into daily weather summaries for the AZMet Bonita and Willcox Bench stations in the Willcox AVA and the AZMet Elgin station in the Sonoita AVA.

View seasonal summaries of monsoon rainfall through regional maps and weather station statistics.

Learn more about PRISM climate data.

Temperatures over the course of this month have a slight increase in chances for being above the 1991-2020 normal across all of Arizona (light-orange and orange areas on map). Monthly average temperatures in October 2025 were 1 to 4 °F above normal for many locations in northwestern, northeastern, and southeastern parts of the state. Otherwise, temperatures were mostly near normal.

Area-average maximum and minimum temperatures during October 2025 were 78.6 and 50.9 °F for the Sonoita AVA, 79.9 and 50.3 °F for the Verde Valley AVA, and 80.9 and 50.2 °F for the Willcox AVA. Respective October normals are 77.3 and 47.5 °F, 80.2 and 47.0 °F, and 79.9 and 46.8 °F.

Temperature in October last year ranged between 89.8 and 39.0 °F at the AZMet Bonita station, between 88.2 and 41.5 °F at the AZMet Elgin station, and between 91.4 and 37.9 °F at the AZMet Willcox Bench station.

Precipitation totals for this month have a slight increase in chances for being above normal across the south-central and southeastern parts of the state (light-aqua area on map). For the rest of Arizona, there are equal chances for below-, near-, or above-normal totals (white area on map). With remnants from two tropical cyclones, precipitation during October 2025 was more than 200 % of normal for a southwest-to-northeast swath across the state. Most of the rest of Arizona measured amounts between 125 and 200 % of normal.

Area-average precipitation totals in October 2025 were 1.76 inches for the Sonoita AVA, 2.33 inches for the Verde Valley AVA, and 1.17 inches for the Willcox AVA. Respective October normals are 0.95, 1.05, and 0.76 inches.

Total precipitation in October last year was 0.70, 1.71, and 0.63 inches at the AZMet Bonita, Elgin, and Willcox Bench stations, respectively.

To stay informed of long-range temperature and precipitation possibilities beyond the coverage of a standard weather forecast, check in, too, with the six-to-ten-day outlook and eight-to-fourteen-day outlook issued daily by NOAA’s Climate Prediction Center.

For this issue, we’ll take a different look at the conditions under which wine grapes ripen. For the past couple of months, the focus was on exposure to daily maximum temperatures above 95 °F and daily minimum temperatures below 65 °F. This month, the focus remains on the months of July, August, and September, when most varieties ripen in most locations during most years. The analysis, however, zooms out from daily details and summarizes seasonal temperature and precipitation from this year in comparison to prior ones. Why all the attention? Because temperature, precipitation, and humidity affect fruit quality and composition.

Compared to the past two vintages, ripening conditions in 2026 are mostly similar to those in 2025 and 2024 for all three Arizona AVAs in terms of maximum and minimum temperatures (top and bottom graphs, respectively). They are not as alike in terms of precipitation, as three-month totals in 2026 were greater, although not among the wettest vintages over the past four-plus decades. Data in these graphs go back to 1981. This means that 2026 conditions are among the hotter vintages, with rainfall amounts neither extremely wet nor extremely dry. To the extent that precipitation and humidity, and perhaps minimum temperature, affect fruit composition, one might expect composition values this year to be different from those of the past two.

Ripening conditions tend to stratify among the three Arizona AVAs, more so with maximum temperature and precipitation (orange, purple, and green points in top graph) than minimum temperature and precipitation (orange, purple, and green points in bottom graph). That is, the Verde Valley AVA generally is warmer and drier than the Willcox AVA, which generally is warmer and drier than the Sonoita AVA. Somewhat counter to this generalization, precipitation totals were similar during the 2026 ripening season in the Verde Valley and Willcox AVAs. Temperatures nonetheless were warmer in the former than in the latter. Comparison of a given variety between these two AVAs from this vintage thus may distinguish effects that temperature has on composition values.

Although we’ve written about this before, it bears repeating that the recent year-to-year volatility in ripening conditions is in line with the expectation for a more variable and extreme summer climate both now and in the coming years. For Arizona viticulture, performance of varieties during these vintages may suggest what their role might be in monsoon hedging and may indicate their future viability.