Plus ALL of these coats and jackets are on sale for 40% off right now (edited to add: sales change constantly at J.Crew so check the site for the latest sale pricing)... so it's a great time to make the investment with such a good discount.
Here I ranked them from least warm to warmest - so depending on what you are looking for you can get an idea of how warm they will be.
(above) Classic Field Jacket
This jacket is coated canvas with no lining. It's a late spring through early fall jacket for me. Perfect for rainy days, a slight chill in the air or just a cool restaurant. I went down a size to an x-small because the small felt huge. So it's quite fitted and works with very thin sweaters or a t-shirt underneath.
(above) Polartec Fleece Pullover
I have three of these total (eep!) and really love them! They wash well and are seriously warm. I find them to be a little oversized so I went down to an XS. This is perfect for chilly fall days, football games or lounging around the house. While it's very warm I never feel overheated in it, it's very comfortable.
above) Quilted Field Jacket
This has been a favorite of mine for several seasons. It's warm and very comfortable and works well with layers. I can easily put a t-shirt or a sweater underneath and be very comfortable. This jacket works for spring through fall. If you lived somewhere warmer this could work as a winter coat too. I also went down a size to an x-small in this one but it's not so fitted like the Classic above.
This coat is about 3-4 years old and it has held up amazing and is still a favorite. It's so beautiful in person and quite warm. I love that it's casual enough to wear everyday but still feels a little dressed up. It is available in literally TONS of colors - all of which are so fun! I've long admired it in black as well. This is another one that fits oversized. You will want to go down a size in this one.
(above) Perfect Winter Parka
This is definitely the warmest of the bunch with a huge fleece lined hood and faux fur hood. It's gorgeous and beautiful which isn't always an easy balance. The coated canvas exterior is water resistant making it ideal for snow or rain and the drawstring waist keeps it looking flattering since it is quite thick. Plus it zippers up really tall so it's perfect for really snowy or cold conditions. If you live somewhere warmer you will likely not need something this warm. If you live in Michigan or somewhere else cold you will love this coat. I also went down a size on this one as it's quite large.
(above) And because this sale is too good to resist I just snagged this white puffer for this season... it's gorgeous in person and while, yes, a white coat will get dirty I will make sure it gets in the wash regularly to keep it looking fresh. I sized down one size to an XS and it fits perfectly even with a sweatshirt underneath. This coat is going to be so warm for this winter! I can't wait to wear it (minus the cold snowy weather!).
(above) Long Puffer Coat
This puffer coat is 3 or 4 years old from J.Crew and it's been a favorite that entire time. It's very warm and gets lots of wear. Plus I've ran it through the washing machine multiple times and it still looks great. The belt really helps keep it looking flattering - I just love a belted coat. It looks like this coat is now available at J.Crew Factory. From what I can tell online it looks exactly the same! And it's a GREAT price! I love when J.Crew brings back old favorites at the Factory. I went down one size in this coat.