I have to go by my experiences in Switzerland, where summer temperatures can also reach over 35. Different grass but you can develop an 'Eye' for a lawn that is thirsty. New lawn: 10mm a day. Measured by laying down a large flat tin. If it needs two hours to fill, thay's how much you water. The problem with a clay substrate is that if drainage is inadequate, you may turn the lawn yellow by over watering. Here again you have to experiment and adjust watering to the season. Fertiliser don't work without water.

That's how I measure. I put small tins all over the lawn let the irrigation system run for a certain time, then measure the water in the tins.

What would you suggest in my case, reducing the watering time every day, or watering less days.

It is taken as a given that less often but then adequate is the idea with irrigation. If you give every day then the grass roots won't be encouraged to go deeper into the soil, which is desirable. As I mentioned above, clay soils with bad drainage can be problematic but I'm sure that once a lawn is established 10 - 20mm a week should be enough.

What happens when you get a downpour? Does water stay on the surface or disappear? If I ever get around to banning the cows from our green bit, I would plugh in 2 - 3 cm of sand before levelling and sowing just because of this.

It is taken as a given that less often but then adequate is the idea with irrigation. If you give every day then the grass roots won't be encouraged to go deeper into the soil, which is desirable. As I mentioned above, clay soils with bad drainage can be problematic but I'm sure that once a lawn is established 10 - 20mm a week should be enough.

What happens when you get a downpour? Does water stay on the surface or disappear? If I ever get around to banning the cows from our green bit, I would plugh in 2 - 3 cm of sand before levelling and sowing just because of this.

This afternoon we had a downpour for over an hour. I estimate at least 5" of water, pool flowing over while backwashing at the same time, if that gives an indication.

On the perimeter wall is a line of dirt about 10 cm above soil level, where the water was during the rain. Less than 30 minutes after the rain finished, no water visible anymore on the lawn.

Of course when you walk you will feel the soil is soaked, but I think that is normal, not?

My location in Chiang Mai has not seen any rain since before November last year.

It is taken as a given that less often but then adequate is the idea with irrigation. If you give every day then the grass roots won't be encouraged to go deeper into the soil, which is desirable. As I mentioned above, clay soils with bad drainage can be problematic but I'm sure that once a lawn is established 10 - 20mm a week should be enough.

What happens when you get a downpour? Does water stay on the surface or disappear? If I ever get around to banning the cows from our green bit, I would plugh in 2 - 3 cm of sand before levelling and sowing just because of this.

Two weeks ago I changed my watering schedule from every day to every other day.

Every other day in the morning between 4.30 and 6.30 am each zone get 21 minutes of water, split up in 3 x 7 minutes.

My lawn has never looked so healthy.

It is taken as a given that less often but then adequate is the idea with irrigation. If you give every day then the grass roots won't be encouraged to go deeper into the soil, which is desirable. As I mentioned above, clay soils with bad drainage can be problematic but I'm sure that once a lawn is established 10 - 20mm a week should be enough.

What happens when you get a downpour? Does water stay on the surface or disappear? If I ever get around to banning the cows from our green bit, I would plugh in 2 - 3 cm of sand before levelling and sowing just because of this.

Two weeks ago I changed my watering schedule from every day to every other day.

Every other day in the morning between 4.30 and 6.30 am each zone get 21 minutes of water, split up in 3 x 7 minutes.

My lawn has never looked so healthy.

Good to hear...Just play your hunches for a while, and you will find the right groove, I am sure.

Hi, any new discoveries for lawn aerators ?  I just joined this forum, and cannot see any post after 2015 on this topic !