September brings many things: a new school year, a new season — and new sales. Before you embark on fall shopping, consult our guide for what you should buy (and skip) as the leaves start to turn and the days grow shorter.

Apple is expected to announce the iPhone 7 in the first week of the month, with an expected release date of mid- to late September, which means retailers will discount last year’s models. If you’re still using the older 5S or 6 version of the phone, this might be the perfect time to upgrade to last year’s 6S/6S Plus model with a two-year contract.

If the savings are anything like they were last year, Apple will reduce the subsidized cost of the older phone — in this case, the iPhone 6S — by $100. Shortly thereafter, it’s likely that other retailers such as Best Buy and Wal-Mart will offer their own deals, likely contingent on signing up for a two-year contract.

There are two excellent times to buy a TV. One is in late November when Black Friday deals begin to roll out, and the other is in late January or early February ahead of the Super Bowl. Because of this, we suggest waiting to do your TV shopping to maximize your savings.

» MORE: What to buy every month of the year

September is a solid time to shop for a mattress. In the week leading up to Labor Day, you’ll start to see significant discounts, which is ideal given that you’ll have plenty of time to test out the various models over the long weekend. Sleep Train is offering up to $400 off select Beautyrest and Posturepedic mattresses and up to $300 off Tempur-Pedic mattresses. During the week of Labor Day, shoppers can also get up to five years of interest-free financing on select mattresses at the store.

It’s that time of the year when retailers pull out their most outrageous holiday displays way too early. Right now, stores are pushing Halloween costumes and fall decor. Your best bet on savings is to shop for decorations and candy after Halloween is over, so if you can wear last year’s costume again this year, go that route.

Don’t limit yourself to items you can place in a shopping cart: There are plenty of other areas where you can save money, including holiday airfare. According to a 2015 study by Expedia, the best time to book domestic flights is 50 to 100 days before your trip, which means if you’re planning to fly around Thanksgiving, you should buy your tickets in September.

Aside from booking for the future, September is an excellent month for traveling if you want to make a last-minute getaway. Last year, companies such as Travelocity and United Airlines offered Labor Day travel deals. And a 2016 analysis by of the best days to fly for summer vacation found that although Labor Day is a pricey day to fly, the middle and end of September are optimal. Sept. 20 is estimated to be the least expensive day of the month to fly.

As of early August, the average family with children in grades K-12 has completed 48% of its back-to-school shopping, according to the National Retail Federation. Nearly 22% haven’t even started yet.

If you still have items to check off, it’s not too late for a bargain. Sales on school supplies will continue into September. At Staples, the 110% price match guarantee runs through Sept. 17. If you buy at Staples and find a lower price at a competitor, you’ll get the lower price plus a refund for 10% of the difference.

Sept. 29 is National Coffee Day. Play it right and you can treat yourself to your favorite cup of joe for free in honor of the caffeine-centric day. Last year, major players in the coffee industry such as Peet’s Coffee & Tea and Krispy Kreme offered freebies. Office supply store Staples hosted a contest to win a coffee prize pack. You may even be able to nab a deal on a coffee maker.

If you miss out on Labor Day sales, you’ll still have a shot at discounted clothing, home decor and appliances. Oct. 10 is Columbus Day, and department stores use the holiday as yet another reason to offer sales.

Courtney Jespersen is a staff writer at NerdWallet, a personal finance website. Email: Twitter: @courtneynerd.

Updated Aug. 24, 2016. 

The article What to Buy (and Skip) in September originally appeared on NerdWallet.