Mother nature doesn't seem to care what time she waters! That's the way I look at it. Really, a lot of times we have rain with the heat of the day, or in the evening, and I've never noticed a problem.
However, I know many will say that diseases can result from watering at night, and I do notice that slugs like daylilies too!
I water when I have the time. If I have the time early in the morning, great, if not, then when I can.
I say it's up to you :)

Cathy

I figure it rains at all times, so we could water at all times. I never water roses at night because it might prompt black spot, but I don't know about problems of that sort with day lilies.
kay

When we're at peak bloom and a lot of visitors are here, I never water in the morning as it damages the blooms. Before there are a lot of blooms though, I do water in the AM - same thing when it's after peak and visitors aren't expected.

I've always read to water in the morning to avoid disease, but my personal opinion is that the water has more time to absorb into the plant overnight before the heat condenses it. I water everything at night with no problem "yet".

I have so many that I water some in the morning and some in the evening. I don't notice a difference. I know hybridizers in the deep south water in the afternoon. They want their plants dry by night to avoid disease. But I think in your climate, night watering shouldn't be a problem.

Debra