You’re right, bunged up nasal passages could well be a cold. The signs and symptoms are alike because cold viruses can also give you rhinitis. But a cold tends to build over a few days and last about a week. Symptoms of seasonal allergies flare up suddenly and drag on for as long as your trigger is in the air.
You may also be confused about the symptoms of seasonal allergies and coronavirus. You can check the up-to-date health information about Covid-19 here.
There are differences in how the two conditions are likely to make you feel. For instance, potential Covid-19 symptoms include body aches. This isn’t usual with seasonal allergies. On the other hand, sneezing is common with hay fever but not Covid-19. If in doubt about what could be causing your symptoms, take a Covid-19 test.