For a day or two, but no longer. There are newer roof underlayments that allow the roof to breath, and can be left uncovered for 6 mo. A big improvement over felt. Consider one of those. GAF Deck Armor is one.
I had a house with #30 felt on it through several light rain storms (very little wind). The felt held up just fine.
But, chances are, if you leave it exposed for more than a day or two (or if it gets wet), you will need to re-do it. Felt wrinkles quickly. Just allow yourself enough time tear off the felt and re-do it if you plan on leaving it there for more than a day or two.
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