Hurricane Katia and Frost

On September 5th, a Gulf of Alaska storm reached 955 mb:
This is Hurricane Katia passing between the Lesser Antilles and Bermuda as a category 3 on September 5th:
It was upgraded to category 4 only for the advisory at 3Z September 6 (10 PM CDT Sept 5) with winds at 115 knots and minimum central pressure 946 mb. Katia on the morning of the 6th:
Morning low temperatures on September 5th were as low as 30F in the Minnesota Arrowhead. On September 15th, International Falls had a low of 19. This was the first time that station had a temperature below 20 for the month of September. Frost advisories (blue) and freeze warnings (light blue) were issued from the Northern Plains to New England:
There was a photo of frost from Sugar Grove, Illinois (west suburb of Chicago) from the 15th on the WGN weather blog.

On September 15th at 21Z (4PM CDT), Tropical storm Maria was upgraded to a hurricane. This may be questionable because the minimum central pressure was 987 mb and the only reasons given in the discussion were satellite and radar imagery. This is how Maria looked at 2145Z (just 45 minutes later):
If hurricane force winds were present, it may have been partly from Maria's movement to the NNE (30 degrees) at 40 mph.