For garlic, did you plant hardneck variety Ladbrokes? They make flower stems in May, scapes which you can snap off to eat, I think that encourages bulbs to swell. Elephant garlic makes a flower stalk in early summer.
For the onions, either you sowed or planted a little early, or.. it is the weather! My overwintered spring onion are fine so far, sown 25th August.