Recent National Weather Service and local model guidance points to a high near 79–82°F for Seattle on August 21 under partly sunny skies, with light northwest flow and limited marine-layer influence keeping conditions warmer than the seasonal 76°F average. Persistent high pressure and clear overnight skies have supported daytime heating, while Puget Sound sea breezes and potential afternoon cloud buildup remain the key variables that could cap or boost readings by a few degrees. Ensemble spreads show modest uncertainty around the 78–81°F range, aligning with the tight clustering of market-implied probabilities across the mid-70s to mid-80s bins; traders appear to be weighting the latest model consensus while monitoring the next NWS update for any shift in steering patterns or boundary-layer moisture.