Heathrow to Euston Railway Station

Approximately what time of day do you anticipate leaving Heathrow--just in case that matters to our Underground experts.

I checked the train schedule and I'm hoping to get a ticket for the 10:30 am or 11:30 am fast train (4.5 hours) to Glasgow. I'd like to get an estimate of how long it would normally take to get from the T4 Underground station to Euston Railway Station if everything went smoothly. I'm an infrequent traveller and I haven't been outside the U.S. in over 40 years, so once I have that estimate I will add a big cushion in case there are delays or I get lost, confused, etc.

If it’s raining, take the tube. If it’s fine, I would walk from King’s Cross. It’s an easy, level 10 maximum minute walk along one straight, busy road (Euston Road) and from memory, it is sign posted at Kings Cross station.

Use tfl.org.uk to plan your journey times. It’s currently suggesting just over an hour to Kings Cross, so allow a few minutes to wait for a train. I would allow 90 minutes.

As you're waking up at Heathrow this is one of those occasions where it makes more sense to fly to Glasgow.

Frequent-flyer tickets are tricky. Sometimes it takes nearly double the miles to go straight to where you want to be.

"The second option is the Piccadilly line to King’s Cross station and walking to Euston. "

I would do this on the day you arrive.
I would not stay at a hotel at the airport.
You could stay at this Premier Inn Euston:
https://www.premierinn.com/gb/en/hotels/england/greater-london/london/london-euston.html?cid=GLBC_LONEUS

From their website:
"Situated on corner of Euston Road (south side) and Duke's Road, between King's Cross/St. Pancras and Euston stations."

You have plenty of time to visit Windsor during your later London stay. As you described your trip, "with the last 2 weeks in London".

If you check into this hotel on your day of arrival, you have nothing to worry about on the second day of your trip regarding getting to Euston station in time to make your train.

From the London Euston Premier Inn website,
"Just down the road from Regent's Park, with the British Museum and the British Library close by"
There's a lot for you to do on your day of arrival after you check into this Euston hotel.

I would agree that it makes more sense to visit Windsor while you are in London for the two weeks at the end.
You're not going to really enjoy trailing miles around a castle while you're jetlagged!
I was just in London in November, and got the tube from Heathrow to Kings' Cross, no changes.
It takes about 60-90 minutes.
If you buy a regular Oyster Card at the Heathrow, you can use it for this train, then use it again for your final two weeks in London.
Just buy it from the ticket desk, and put about twenty pounds on it to start.
Euston is right next door to King's Cross, and I wouldn't even say it was as far as a ten minute walk.
You do not have to get to KC, then get another Tube to Euston.
However: it would be much easier for you to get in to a hotel near the two stations on your first night, then relax a bit in London, then go up to Glasgow by train.
There is a Premier Inn right by the two stations.
Happy planning, and let us know what else we can help you with!

There are several Premier Inns near King's Cross station. The one I gave you in my first post above.
And this one, a bit newer,
directly across the street from King's Cross/St Pancras station:
https://www.premierinn.com/gb/en/hotels/england/greater-london/london/london-kings-cross.html?cid=GLBC_KINPTI

I like that it is newer than the other Premier Inn, but still in a good location for you.

Rebecca, Thank you. You make a good point. However, the current difference in rates at the Heathrow T4 hotel and the Euston hotel is £88, or $116, which is a lot of extra money when I don’t have want or need to go downtown on the day I arrive. I've been advised by friends that with an overnight flight, the best way to fight jet lag is to go out a walk all day and then go to bed early, so Windsor seems like a good option for me on that first day.

I totally understand (and agree) the difference in price between the Premier Inns is a factor, and that you don't really need to go into London the first day. Just trying to be helpful with suggestions.

Yes, I agree that Windsor is a good place to walk off jet lag that day!
We spent a day in Windsor last spring at the end of our Rick Steves tour, and enjoyed seeing Windsor Castle and walking around the town.
There are a number of good pubs and cafes there for lunch.
I recommend the Cornish Pastie shop on Peascod St. or same name shop in the train station.
Inexpensive, delicious, and you can carry it out with you, saving the surcharge put onto a sit-down meal.
Have a good trip!

S J, you may be getting your stations mixed up.

There are three stations along that stretch of Euston Road, two together and one the other side of a housing estate. Kings Cross and St Pancras International are across the road from one another and share one Kings Cross St Pancras Underground station.

Along Euston road, past the British Library, past the Premier Inn on one side and the Pullman on the other, past the union headquarters and the fire station is Euston Station.

You can walk along Euston Road or walk through the housing estate. I walk through the neighbourhood (sticking to the roads not the houses) but only in the daytime. I tend not to walk though any housing estates I don't know at night. It takes me a little longer than 10 minutes to do the Euston walk with no luggage.

Piccadilly line Terminal 3 to Kings Cross St Pancras is timetabled at 55 minutes. From Terminal 5, 58 minutes. Terminal 4 is 61 minutes.

Nigel, you are right!
Thank you.
Hadn't had my coffee yet....!

Let me give you another option.......

When you arrive at Heathrow, stow your bags and go visit Windsor.

Then, later in the afternoon, or early evening, take a flight to Glasgow. You are already at the airport. Rather than spend a whole day traveling by train, take a short flight and you'll have an extra day in Glasgow. There is a bus from the airport to downtown.

Frank, thank you for the suggestion. However, I don't think it's a desirable option for me. Flying is more expensive than an Advance train ticket. But more importantly, I'll be pushing the limits of my endurance by the time I return from Windsor, assuming I have the energy to do that. It might be an option if I had a direct flight from the U.S., but I don't. I have to get up Wednesday around 4 am in the U.S., change planes with a 5 hour layover, and then take a 9+ hour flight to London. I don't expect to get much sleep on the plane, so I don't think I'll be ready for any more challenges on my day first day in England.

Thank you to everyone for your thoughtful comments, especially Rebecca and S.J. Having a different perspective was very helpful. I made a reservation at a hotel within easy walking distance of the Euston Train Station. Once I buy my train ticket, I'll cancel the airport hotel.