Washington: Today - Sunny, high in the mid 80s, low 65 to 70. The chance of rain is 10 percent today, near zero tonight. Winds will be light and variable. Tuesday - Partly cloudy and warmer, high near 90.

Maryland: Today - Sunny, high in the low to mid 80s, low in the mid to upper 60s. Tuesday - Partly cloudy and warmer, high in the mid to upper 80s.

Virginia: Today and Tuesday - Partly cloudy, high in the mid to upper 80s, low in the 60s.

Lower Potomac and Chesapeake Bay - Fair with visibility of 5 miles or more diminishing to less than 3 miles in haze. Winds will be northerly at 10 to 15 mph shifting to the northeast at 10 mph. Waves will average 1 to 2 feet.

Atlantic Ocean Beaches from New Jersey to Maryland: Today - Mostly sunny, high in the 70s. Tuesday - Partly cloudy, high in the low 80s. Water temperatures will average in the mid 70s.

Atlantic Ocean Beaches from Virginia to North Carolina: Today and Tuesday - Partly cloudy, high in the 80s. Water temperatures will range from the upper 70s to the low 80s.

West Virginia: Today - Partly cloudy, high in the 70s, low in the 50s. Tuesday - Sunny, highs from the mid 70s to low 80s.

Extended Area Forecast for Wednesday through Friday - Fair through the period. Highs will range from the upper 70s to mid 80s, lows in the 60s. Normal Washington temperatures for the period are a high of 83 and a low of 64.

The National Weather Forecast for today - Showers and thunderstorms will range across the Pacific Northwest, over portions of Texas, from the lower Great Lakes through northern New England and from the Carolinas through eastern Alabama and Florida. There will be widely scattered thundershowers from the northern Rockies into Montana, across the southern Plateau and the southern Rockies. In the central Plains and the lower Mississippi Valley. Temperatures will be mild from northern California through western Washington state and from New Mexico across Texas. Hot temperatures will prevail through southern California and southwestern Arizona, the northern and central Plains and the Mississippi Valley. Most of the remainder of the nation will remain warm.

Almanac Data for today: The sun rises 6:39 a.m., sets 7:34 p.m.; moon rises 8:29 a.m., sets 8:40 p.m.

Tides: High 9:51 a.m. and 10:14 p.m., low 4:30 a.m. and 4:44 p.m. High and low tides at the following locations may be obtained by subtracting the hours indicated from the hours above: Annapolis (3 1/4), Bloody Point Lighthouse (4 1/2), Deale, Md. (4 1/2), Colonial Beach (5 1/4), Norfolk (1), Virginia Beach (3/4), Solomons Island (6 1/4), Point Lookout (7).

The Council of Governments' Air Quality Index for yesterday showed the high reading in the Washington area during the 1 p.m. period was 50 for the pollutant, photochemical oxidants. Index values between 50 and 100 indicate unhealthy air quality. When the index exceeds 100 the air is considered very unhealthy and individuals with lung, heart and eye ailments are urged to restrict their activity. The forecast for today indicates that the air quality will remain about the same.

The National Weather Services forecasts the Potomac River Stage at Little Falls should decrease to near 3.6 feet today.

Washington data for yesterday: Highest temperature since midnight yesterday, 87 degrees at 3:45 p.m. Lowest temperature since midnight, 70 degrees at 4:40 a.m. Excess of temperature since Sept. 1, 6 degrees. Excess of temperature since Jan. 1, 4 degrees. Record high temperature for today, 94 degrees in 1970. Record low temperature for today, 49 degrees in 1908. Relative humidity: maximum, 84 percent at 5 a.m.; minimum, 52 percent at 4 p.m. 24 hour precipitation, none. Deficiency of precipitation since Sept. 1, 38 inches. Excess of precipitation since Jan. 1, 3.49 inches. Highest observed wind since 8 a.m., 15 miles per hour from the northwest at 4 p.m. Peak gust since 8 a.m., 21 miles per hour from the north at 4:10 p.m. Local Temps., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 midnt(COLUMN)73(COLUMN)76 1 a.m.(COLUMN)73(COLUMN)76 2 a.m.(COLUMN)72(COLUMN)79 3 a.m.(COLUMN)71(COLUMN)82 4 a.m.(COLUMN)71(COLUMN)82 5 a.m.(COLUMN)70(COLUMN)84 6 a.m.(COLUMN)70(COLUMN)84 7 a.m.(COLUMN)71(COLUMN)82 8 a.m.(COLUMN)71(COLUMN)82 9 a.m.(COLUMN)74(COLUMN)74 10 a.m.(COLUMN)78(COLUMN)65 11 a.m.(COLUMN)80(COLUMN)63 12 noon(COLUMN)81(COLUMN)61 1 p.m.(COLUMN)82(COLUMN)59 2 p.m.(COLUMN)85(COLUMN)53 3 p.m.(COLUMN)85(COLUMN)53 4 p.m.(COLUMN)86(COLUMN)52 5 p.m.(COLUMN)86(COLUMN)52 6 p.m.(COLUMN)84(COLUMN)57 7 p.m.(COLUMN)83(COLUMN)57(END TABLE) Temperatures ending 8 a.m. (EDT) yesterday:(TABLE) City(COLUMN)H.(COLUMN)L Albany(COLUMN)79(COLUMN)56 Albuquerque(COLUMN)86(COLUMN)61 Amarillo(COLUMN)90(COLUMN)68 Anchorage(COLUMN)68(COLUMN)50 Asheville(COLUMN)76(COLUMN)66 Atlanta(COLUMN)87(COLUMN)69 Atlantic City(COLUMN)73(COLUMN)62 Austin(COLUMN)91(COLUMN)72 Baltimore(COLUMN)81(COLUMN)61 Billings(COLUMN)92(COLUMN)65 Birmingham(COLUMN)84(COLUMN)65 Bismarck(COLUMN)92(COLUMN)60 Boise(COLUMN)93(COLUMN)64 Boston(COLUMN)80(COLUMN)62 Brownsville(COLUMN)92(COLUMN)75 Buffalo(COLUMN)79(COLUMN)60 Burlington, Vt.(COLUMN)79(COLUMN)61 Casper(COLUMN)89(COLUMN)53 Charleston, S.C.(COLUMN)87(COLUMN)76 Charleston W.Va.(COLUMN)82(COLUMN)67 Charlotte(COLUMN)82(COLUMN)71 Cheyenne(COLUMN)86(COLUMN)51 Chicago(COLUMN)88(COLUMN)68 Cincinnati(COLUMN)79(COLUMN)53 Cleveland(COLUMN)81(COLUMN)57 Columbia, S.C.(COLUMN)88(COLUMN)69 Columbus(COLUMN)81(COLUMN)55 Dal.-Ft. Worth(COLUMN)91(COLUMN)70 Dayton(COLUMN)77(COLUMN)55 Denver(COLUMN)91(COLUMN)58 Des Moines(COLUMN)87(COLUMN)64 Detroit(COLUMN)85(COLUMN)68 Duluth(COLUMN)84(COLUMN)51 El Paso(COLUMN)86(COLUMN)61 Evansville(COLUMN)86(COLUMN)58 Fairbanks(COLUMN)70(COLUMN)48 Fargo(COLUMN)89(COLUMN)60 Flagstaff(COLUMN)80(COLUMN)45 Great Falls(COLUMN)95(COLUMN)54 Hartford(COLUMN)81(COLUMN)56 Helena(COLUMN)95(COLUMN)53 Honolulu(COLUMN)88(COLUMN)75 Houston(COLUMN)88(COLUMN)76 Indianapolis(COLUMN)83(COLUMN)58 Jackson(COLUMN)87(COLUMN)70 Jacksonville(COLUMN)93(COLUMN)72 Juneau(COLUMN)68(COLUMN)46 Kansas City(COLUMN)88(COLUMN)72 Las Vegas(COLUMN)105(COLUMN)79 Little Rock(COLUMN)84(COLUMN)72 Los Angeles(COLUMN)84(COLUMN)67 Louisville(COLUMN)82(COLUMN)60 Memphis(COLUMN)84(COLUMN)68 Miami Beach(COLUMN)86(COLUMN)80 Midland(COLUMN)88(COLUMN)66 Milwaukee(COLUMN)82(COLUMN)68 Mpls.-St. Paul(COLUMN)89(COLUMN)60 Nashville(COLUMN)85(COLUMN)60 New Orleans(COLUMN)90(COLUMN)72 New York(COLUMN)78(COLUMN)65 Norfolk(COLUMN)81(COLUMN)64 North Platte(COLUMN)94(COLUMN)53 Oklahoma City(COLUMN)96(COLUMN)73 Omaha(COLUMN)85(COLUMN)65 Orlando(COLUMN)95(COLUMN)74 Philadelphia(COLUMN)82(COLUMN)64 Phoenix(COLUMN)106(COLUMN)82 Pittsburgh(COLUMN)80(COLUMN)56 Portland, Me.(COLUMN)77(COLUMN)57 Portland, Ore.(COLUMN)76(COLUMN)60 Providence(COLUMN)77(COLUMN)57 Raleigh(COLUMN)80(COLUMN)68 Rapid City(COLUMN)94(COLUMN)65 Reno(COLUMN)90(COLUMN)54 Richmond(COLUMN)84(COLUMN)66 St. Louis(COLUMN)89(COLUMN)68 St. Prbg.-Tampa(COLUMN)92(COLUMN)75 Salt Lake City(COLUMN)95(COLUMN)67 San Antonio(COLUMN)89(COLUMN)71 San Diego(COLUMN)78(COLUMN)69 San Francisco(COLUMN)63(COLUMN)58 San Juan(COLUMN)90(COLUMN)76 St. Ste. Marie(COLUMN)78(COLUMN)54 Seattle(COLUMN)73(COLUMN)59 Shreveport(COLUMN)87(COLUMN)69 Sioux Falls(COLUMN)91(COLUMN)63 Spokane(COLUMN)82(COLUMN)55 Syracuse(COLUMN)81(COLUMN)62 Topeka(COLUMN)92(COLUMN)66 Tucson(COLUMN)97(COLUMN)77 Tulsa(COLUMN)98(COLUMN)75 Washington(COLUMN)84(COLUMN)70 Wichita(COLUMN)98(COLUMN)70(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)H.(COLUMN)L. Acapulco(COLUMN)pt. cldy(COLUMN)88(COLUMN)77 Barbados(COLUMN)pt. cldy(COLUMN)86(COLUMN)76 Bermuda(COLUMN)fair(COLUMN)86(COLUMN)80 Calgary(COLUMN)pt. cldy.(COLUMN)81(COLUMN)43 Edmonton(COLUMN)cloudy(COLUMN)79(COLUMN)48 Havana(COLUMN)cloudy(COLUMN)86(COLUMN)76 Kingston(COLUMN)fair(COLUMN)90(COLUMN)79 Montego Bay(COLUMN)cloudy(COLUMN)90(COLUMN)76 Mexico City(COLUMN)cloudy(COLUMN)70(COLUMN)55 Monterray(COLUMN)fair(COLUMN)94(COLUMN)72 Montreal(COLUMN)cloudy(COLUMN)77(COLUMN)61 Nassau(COLUMN)pt. cldy.(COLUMN)90(COLUMN)73 Ottawa(COLUMN)rain(COLUMN)79(COLUMN)61 Regina(COLUMN)clear(COLUMN)86(COLUMN)55 St. Kitts(COLUMN)fair(COLUMN)90(COLUMN)77 St. Thomas(COLUMN)pt. cldy(COLUMN)87(COLUMN)77 Toronto(COLUMN)pt. cldy(COLUMN)84(COLUMN)63 Vancouver(COLUMN)rain(COLUMN)64(COLUMN)57 Veracruz(COLUMN)cloudy(COLUMN)86(COLUMN)70 Winnipeg(COLUMN)clear(COLUMN)75(COLUMN)52(END TABLE)