Fall color in the Cottonwood Canyons is forecast to peak around Sept. 30 through Oct. 6, according to county-by-county predictions from MoreThanJustParks.com.

The forecast was cited in a Salt Lake Tribune report published Wednesday, Sept. 9. OpenSnow meteorologist Alan Smith offered a slightly later window, forecasting early to mid-October for peak color across the Northern Utah Wasatch in a separate fall foliage outlook published Aug. 31.

Both forecasters cautioned that the dates are rough guides. MoreThanJustParks.com noted its predictions could be off by up to 15 days in either direction because it has no calibration sites in the West.

Evan Thayer, OpenSnow's Utah forecaster, called the Cottonwood Canyons "always a safe bet for seeing the leaves change" in the Tribune report. Red bigtooth and Rocky Mountain maples are the first trees to signal autumn at middle and upper elevations, he said, starting in mid-September. Quaking aspen follow as color spills downhill.

Thayer told the Tribune that weather during the color change matters most. "A storm with high winds can ruin an otherwise good foliage year prematurely," he said.

Smith said severe to extreme drought conditions across Utah may make colors less vibrant than usual. But August rain helped. Utah received an inch more rain than the August median, a 55.5% increase, according to the Natural Resources Conservation Service. July also exceeded the median by almost an inch.

Smith said warm days and cool nights in late summer can make leaves more vibrant. Utah had those conditions through August and early September, he said. Many trees also leafed out early during the state's record-warm winter, which Smith said typically means an earlier color change in fall.

Sandy residents heading up Big or Little Cottonwood Canyon can expect golds from quaking aspen and narrowleaf cottonwoods, plus reds and oranges from maples and Gambel oak.

Smith's Fall Colors Map on OpenSnow updates twice weekly for anyone tracking conditions as the peak window approaches.