Cold air starts to spill southward on Sunday, January 20, 2013, the day before the inauguration. (, adapted by CWG)

The Arctic floodgates open Sunday, sending a rush of chilly air towards Washington, D.C. just in time for President Obama’s second inauguration.

Link: Washington, D.C. presidential inauguration weather history

Fortunately, for those attending related festivities, the core of the arctic air will not arrive until Tuesday, when highs will only be in the 20s. We expect high temperatures to be in the mid-to-upper 30s for inauguration day, Monday, January 21.

(, adapted by CWG)

Hour by hour detail

Note: Given forecast winds around 10 mph, the wind chill factor will make these temperature feel about 5-10 degrees colder.

4-8 a.m.: Metro opens at 4 a.m. For those heading out early to stake out a prime spot to watch the swearing-in ceremony, temperatures will start the day between 25 and 30 degrees. Sky conditions: mostly clear. Winds: from the north at 5-10 mph.

8 a.m.-noon: Temperatures should rise slowly above the freezing mark, climbing from around 30 to 35 degrees. Our estimated swearing-in temperature is 35. This is 7 degrees warmer than Obama’s first inauguration noon temperature of 28. Sky conditions: partly to mostly sunny. Winds: from the northwest at around 10 mph.

Noon to 4 p.m.: Afternoon temperatures should mainly hold in the mid-to-upper 30s for those attending the parade. Upper level energy scooting by to our north might squeeze out a snow shower or flurry, especially towards the late afternoon hours. Sky conditions: Variably cloudy. Winds: from the northwest at around 10 mph.

(, adapted by CWG)

4 p.m.-8 p.m.: Temperatures slide downward, back below freezing into the upper 20s by 8 p.m. Heavy coats for those of you attending inaugural balls. A snow flurry cannot be ruled out - no accumulation expected. Sky conditions: Variably cloudy. Winds: from the northwest at around 5-10 mph.

8 p.m.-midnight: The steady downward slide in temperatures continue, into the mid-20s by the day’s close. Sky conditions: Partly cloudy. Winds: from the northwest at around 5-10 mph.

Five tips for staying toasty

I should stress this will be among the coldest days of winter thus far and many will not be acclimated to these temperatures, particularly for prolonged intervals. While it will not be as cold as Obama’s 2009 inauguration (noon temperature of 28), dress like it.

I’m republishing the recommendations CWG contributor Ann Posegate provided 4 years ago:

1) Check our forecast. Plan for the temperature to feel at least 10 degrees colder than predicted, especially if you will be outside for hours at a time. Also be sure to take into account wind chill -- what the temperature feels like to your body with wind and temperature combined. (Here’s a calculator.)

2) Wear layers and cover as much exposed skin as possible. If you step outside and immediately feel cold, you’re not wearing enough layers. Wear layers (including a base layer like thermal underwear), bring an extra warm layer with you, and wear a wind-proof outer layer if you have one. Wool, fleece, and synthetic fibers are generally warmer than cotton. Wear tight-fitting sleeves and tuck in your shirt to prevent cold air from sneaking in. A scarf, hat, gloves and thick socks are essential: they cover the parts of your body that lose heat the fastest. You might also consider buying toe and hand-warmers -- inserts for your gloves and shoes that cost under a few dollars, but last for hours! They can be found at sports and outdoor clothing stores throughout the area.

3) Get plenty of rest, eat well and stay hydrated. These basic wellness tips especially apply to cold weather. High-calorie, well-balanced meals, warm liquids and water are fuel. Your body has to work to stay warm, and taking care of it will help it work better.

4) Stay warm first, look cool second. Image is not everything, especially when it’s cold out. Ladies, you may want to consider doubling-up on stockings, or wearing pants and shoes on your way to an event (wearing a long dress and long coat will help this look less awkward -- most events will have a coat check). You might also want to wear a shawl in case the event room is not well-heated. At the least, wear boots or tennis shoes and bring along dress shoes...I welcome other suggestions! Men, wear thick socks, and a suit liner or extra layer under your suit.

5) Use your better judgment. If you are persistently shivering, or if your skin feels cold despite your many layers of clothing, consider going indoors for a while. Also, keep an eye out for the person standing next to you, since a cold body temperature can impair judgment. If it’s just too cold to bear, you can always watch the major events from home.

Oh, and one more thing: you may want to bring tissues or a handkerchief -- there’s a good chance of cold, runny noses!