Does weather affect spread of the coronavirus outside?

So the quick answer is no, then.

And the long answer is... no, not if you follow the not-very-difficult-for-most health advice.

"Great homogeneity was observed in the findings regarding the effect of temperature and humidity on the seasonal viability and transmissibility of COVID-19. Cold and dry conditions were potentiating factors on the spread of the virus"

"Considering the existing scientific evidence, warm and wet climates seem to reduce the spread of COVID-19"

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0238339

"Considering the existing scientific evidence, warm and wet climates seem to reduce the spread of COVID-19"

The important part is the last word of the title in the article. It is already well known that low temperature and humidity facilitate the spreading of the infection... on the typical environments where is common (indoors, close proximity)

Since activity outdoors relatively has a much lower risk, it is very difficult to examine if the conditions of the weather affect this risk or not. Normal variation between situations (number of people, distance between them, time of the interaction) is likely much more important so it becomes impossible to see if a couple of degrees or percentage points are important.