Is there a temperature too hot , or too cold; when you should not walk on a asphalt shingle roof?
If to hot you could smear the shingles when walking on them…
I don’t think that there’s a set temperature guideline but you do need to remember that shingles change based on the temp.
Too Hot and you can easily scrape off the granules, cold shingles are brittle and can break easier if not careful. You also need to watch for ice in freezing temperatures.
Jeff, complete the InterNACHI Asphalt Shingle Inspection video course and you won’t need to ask other people for answers to questions like that.