I will be arriving at the new airport at around 1 pm, weekday. Will it be crowded then?

Thanks in advance for infos.

:-)

Middle of the day, any major airport will be busy. Just use common sense, watch belongings, ignore taxi touts the usual stuff, you'll be fine

I didn't think it was particularly crowded at that time of day when I've seen it. The busiest I've seen it is in late afternoon. But anyways, the arrival hall will likely be crowded at almost anytime you arrive, being there's always lots and lots of touts blocking everyone's way there. Just ignore them, or run over them with your trolley if you can , and make your way quickly to the next level either up or down. As soon as you get off the arrivals level 2, it shouldn't be very bad regardless of what time you arrive.

If you want a metered taxi from the taxi booth, go down to level 1. If you want to catch an arriving metered taxi letting off passengers, head up to level 4 and save the 50 baht surcharge. If you want to pay more for an official AoT limousine taxi, they should have someone there right as you exit customs, before the massive crowds.

The crowded arrival hall can be a bit intimidating for a first timer to Suvarnabhumi, but after a while you get used to it and it's not really a big deal unless you let it bother you.