PigletJohn or other knowledgeable people- a question

[everywoman682]

Since the first heatwave our cold water taps have been running warmer than usual. Not actually warm, but definitely not as cold as normal. Our plumbing doesn't have any cold water pipes too close to hot pipes: the water warming up has never been an issue previously.
My take on it is that somewhere in the system, the pipes into the house must be near enough to the ground surface that they've absorbed heat through the ground, but on the other hand surely water pipes are laid quite deep and shouldn't be affected by air temperature? If they're too near the surface surely there would be the opposite risk of freezing when temperatures are sub zero?
Can anyone enlighten me? And any idea how long for my water temperature to return to normal?
TIA

Isn't this a standard thing for everyone every summer?
I would guess that the water coming into your house from the water processing place is warmer than normal and as it isn't sat in the pipes for long, because water usage is high, it doesn't cool down to ground temp before it is used? Is it cooler first thing in the morning?

I thought this was completely normal? A boiler engineer turned down the temp of our hot water but warned me that the outdoor temperature would have an effect too as the cold water the boiler was heating would be warmer in the summer months than it was in the winter.

My cold water also runs hot in the summer. I just give it a while running and then it's cold. I just assume the pipes where the water enters the house are heated by the sun and running it through brings the water from deeper pipes up.

Do you have a loft tank and if so, is it ALL cold taps (see where I'm going here)?

Normal! You can always fill a bottle with tap water and keep in the fridge.

Yup, it's normal.
(I've worked in the water industry).

The only thing water companies insist on is that new water supply pipes (the ones leading up to your house) are 2ft 6in deep to protect against frost. Obviously there's older pipes that are a lot shallower than that.

Yes, the best thing about winter is lovely cold water from the cold tap. Mine feels very warm atm.

Thanks all!
@Dogtooth I always drink water from the fridge; it's washing that I find more of a pain... I always finish showering on a cold setting during the summer and I'd noticed it wasn't the usual refreshing cold blast!

The point I was getting at is whether you had a loft tank in the (recently very hot) loft?

Fresh water comes straight off the incoming supply and I have never lived anywhere where this is anything but nice and cold (after it has been run for a second or two) regardless of the ambient temperature.
If you have a loft tank then everything other than the kitchen cold tap is likely to be fed from this and with the high temperatures we have had lately the water in this tank will be (a lot) warmer than usual (loft spaces can be horrible places on a hot day and retain the heat) the shear volume of water retaining the temperature in the tank even as it is used / topped up.

Of course, if you don't have a loft tank and instead have a combi or Indirect system then ignore what I have said as it is not relevant. 😭

Surely water temp in wont make any difference, the boiler just heat its to s et temp. If its set at 60c then it will stop heating the water when it gets to 60c. If the incoming water is 5c or 40c it will still heat it to 60c.

It's an oil fired boiler that lives outside, the water does seem slightly hotter in warmer weather, in the winter I have to boil the kettle to get the water good and hot to wash up in but in the summer I don't.