Southern Oregon will begin the week with a brief chance of mountain showers Sunday before dry weather and rising temperatures carry the region into October. The warmest afternoons are expected Wednesday and Thursday, when Grants Pass could reach the 90s. Road construction north of Grants Pass and along the southern coast remains the chief travel concern.
Sunday, September 27, brings a mix of sun and clouds, with highs near 82 degrees in Grants Pass, 78 in Medford, 74 in Roseburg and 68 in Klamath Falls. Brookings is expected to reach about 61. Isolated showers may develop during the afternoon and evening along the Cascades and in parts of Lake County, with a few thunderstorms possible over higher terrain. Most communities west of the Cascades are expected to remain dry.
The chance of showers fades overnight, leaving Monday, September 28, mostly sunny across the region. Afternoon highs should reach about 85 in Grants Pass, 80 in Medford and 71 in Klamath Falls. Early travelers will encounter much cooler conditions, particularly east of the Cascades, where Klamath Falls could start the day in the mid-30s. Low clouds or fog may also form near the coast. Gusty north winds and steep seas will continue to affect coastal waters into Monday.
Temperatures climb again Tuesday, September 29, as a weakening weather front stays north of Southern Oregon. Grants Pass is forecast near 89 degrees, Medford near 80, Roseburg near 78 and Klamath Falls near 74. Brookings could reach the lower 70s. No widespread rain is expected, leaving weather-related interruptions unlikely on the region’s main highway routes.
Wednesday, September 30, is expected to bring mostly sunny skies and the start of the week’s hottest stretch. Grants Pass could reach the lower 90s, while Medford rises to about 84 and Klamath Falls to 76. Brookings may reach 76 as well. On Interstate 5 between Grants Pass and Hugo, motorists should be prepared to slow for work between mileposts 58 and 67, where intermittent lane, shoulder and ramp closures remain scheduled.
The warmth continues Thursday, October 1, with a forecast high near 94 in Grants Pass. Medford could reach 86, Roseburg 80 and Klamath Falls 82. Cool mornings will give way to substantially warmer afternoons in the inland valleys. Drivers crossing the Cascades or traveling between the coast and interior should expect temperatures to change considerably along their routes, even as dry weather persists.
A slight cooling trend arrives Friday, October 2. Grants Pass is forecast near 82 degrees, Medford near 81 and Roseburg near 76, with partly sunny skies and little prospect of rain. Interstate 5 ramp closures north of Grants Pass are listed through Friday at exits 58, 61 and 66. The closures are intermittent and generally scheduled overnight, so travelers using those interchanges should allow for a possible change in route.
Saturday, October 3, brings another modest rise in temperatures. Highs are forecast near 85 in both Grants Pass and Medford, 78 in Roseburg and 80 in Klamath Falls. Brookings should reach about 70. Along U.S. 101, construction near Gold Beach and Brookings may delay coastal trips. South of Gold Beach, a single lane controlled by flaggers has produced estimated delays of less than 20 minutes.
By Sunday, October 4, warm and largely dry conditions are expected to close the week. Grants Pass could reach 88 degrees, Medford 89, Roseburg 84 and Klamath Falls 80, while Brookings remains cooler near 66. For longer trips north, the southbound Interstate 5 closure through Portland’s Rose Quarter remains in effect, with traffic directed to posted detours.