Washington: Today - Humid, high in low 90s, low in low to mid 70s. Chance of rain near zero today, 10 per cent tonight. Tuesday - Humid, chance of afternoon or evening showers, high in low 90s.

Maryland and Virginia: Today - Humid, highs in mid 80s to low 90s, lows in mid 60s to low 70s. Chance of afternoon or evening showers in mountains. Tuesday - Humid with chance of rain, highs in mid 80s to low 90s.

Lower Potomac and Chesapeake Bay: Today - Fair skies with good visibility through tonight. Winds should be southwesterly at up to 12 knots this afternoon, diminishing tonight.

Extended Area Outlook: For Wednesday through Friday - Fair chance of afternoon and evening showers Wednesday. Highs should average near 90, lows in mid 60s to low 70s. Washington's normal temperature range for this time of year is from 84 to 65.

West Virginia: Today - Partly cloudy and humid with chance of late afternoon and evening showers, highs from lows 80s to low 90s, lows from mid 60s to mid 70s. Tuesday - Partly cloudy and humid, chance of rain, highs from low 80s to low 90s.

Atlantic Ocean Beaches from day - Humid, highs in 80s. Tuesday - Humid in south, chance of rain in north, highs in 80s. Water temperatures should range from low 70s in north to near 80 in south both days.

The National Weather Forecast for Today - Scattered showers and thunderstorms are likely over most of the eastern third of the country from the upper Great Lakes to Maine and southward to the Gulf of Mexico excluding the middle Atlantic Coast states, from the middle Mississippi Valley through western Texas and from central Montana through Oregon and Washington State. Mild to cool temperatures can be expected from the Mississippi Valley to the Pacific Coast with the exception of southern Texas, Arizona and most of California. Most of the remainder of the nation will be seasonably warm to hot.

Almanac data for Monday, Aug. 29, 1977. Sun rises 6:34 a.m., sets 7:43 p.m.; moon rises 8:05 p.m., sets 7:22 a.m. Tides: High 9:15 a.m. and 8:44 p.m., Low 3:29 a.m. and 3:00 p.m. High and low tides at the following locations can be obtined by subtracting the hours indicated from the tides above. Annapolis (3 1/2); Bloody Point Lighthouse (4 1/2); Deale, Md. (4 1/2); Colonial Beach (6); Norfolk (1 1/2); Virginia Beach (1); Solomons Island (6 1/2); Point Lookout (7).

The Council of Governments' Air Quality Index for yesterday showed the high reading in the Washington area during the noon period was 100 for the pollutant, photochemical oxidants. Index values between 100 and 249 indicate very 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 National Weather Service forecasts the Potomac River stage at Little Falls should remain near 2.7 feet today.

Washington data at 8 p.m. (EDT) yesterday: Highest temperature since 8 a.m. yesterday, 90 degrees at 3:10 p.m. Lowest temperature since midnight, 70 degrees at 6:28 a.m. Excess of temperature since Aug. 1, 39 degrees. Excess of temperature since Jan. 1, 316 degrees. Record high temperature for today, 98 degrees in 1953. Record low temperature for humidity: Maximum, 100 per cent at 5 a.m.; Minimum, 56 per cent at 3 p.m. 24 hour precipitation, none. Excess of precipitation since Aug. 1, .07 inches. Deficiency of precipitation since Jan. 1, 6.41 inches. Highest observed wind since 8 a.m. 12 miles per hour from the south at 6 p.m. Peak gust since 8 a.m., 16 miles per hour from the south at 2:30 p.m. Local Temp., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 midnt.(COLUMN)75(COLUMN)91 1 a.m.(COLUMN)74(COLUMN)94 2 a.m.(COLUMN)74(COLUMN)90 3 a.m.(COLUMN)73(COLUMN)93 4 a.m.(COLUMN)72(COLUMN)93 5 a.m.(COLUMN)71(COLUMN)100 6 a.m.(COLUMN)71(COLUMN)100 7 a.m.(COLUMN)70(COLUMN)100 8 a.m.(COLUMN)73(COLUMN)94 9 a.m.(COLUMN)75(COLUMN)83 10 a.m.(COLUMN)78(COLUMN)79 11 a.m.(COLUMN)81(COLUMN)72 12 noon(COLUMN)84(COLUMN)68 1 p.m.(COLUMN)87(COLUMN)61 2 p.m.(COLUMN)88(COLUMN)57 3 p.m.(COLUMN)89(COLUMN)56 4 p.m.(COLUMN)89(COLUMN)56 5 p.m.(COLUMN)88(COLUMN)57 6 p.m.(COLUMN)87(COLUMN)59(END TABLE) Temperatures ending 8 a.m. (EDT) Yesterday(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)81(COLUMN)67 Albuquerque(COLUMN)87(COLUMN)62 Amarillo(COLUMN)88(COLUMN)67 Anchorage(COLUMN)67(COLUMN)54 Asheville(COLUMN)80(COLUMN)68 Atlanta(COLUMN)86(COLUMN)70 Atlantic City(COLUMN)78(COLUMN)71 Austin(COLUMN)93(COLUMN)77 Baltimore(COLUMN)86(COLUMN)67 Billings(COLUMN)69(COLUMN)48 Birmingham(COLUMN)90(COLUMN)75 Bismarck(COLUMN)66(COLUMN)49 Boise(COLUMN)66(COLUMN)52 Boston(COLUMN)85(COLUMN)69 Brownsville(COLUMN)90(COLUMN)74 Biffalo(COLUMN)87(COLUMN)75 Burlington, Vt.(COLUMN)82(COLUMN)72 Casper(COLUMN)68(COLUMN)42 Charleston, S.C.(COLUMN)88(COLUMN)78 Charleston, W. Va.(COLUMN)88(COLUMN)69 Charlotte, N.C.(COLUMN)89(COLUMN)73 Cheyenne(COLUMN)65(COLUMN)47 Chicago(COLUMN)93(COLUMN)75 Cincinnati(COLUMN)87(COLUMN)73 Cleveland(COLUMN)87(COLUMN)73 Columbia, S.C.(COLUMN)89(COLUMN)72 Columbus, Ohio(COLUMN)87(COLUMN)73 Dal.-Ft. Worth(COLUMN)96(COLUMN)74 Dayton(COLUMN)87(COLUMN)72 Denver(COLUMN)87(COLUMN)72 Des Moines(COLUMN)90(COLUMN)66 Detroit(COLUMN)93(COLUMN)74 Duluth(COLUMN)73(COLUMN)61 El Paso(COLUMN)91(COLUMN)76 Fairbanks(COLUMN)61(COLUMN)39 Fargo(COLUMN)63(COLUMN)56 Flagstaff(COLUMN)75(COLUMN)43 Great Falls(COLUMN)64(COLUMN)41 Hartford(COLUMN)85(COLUMN)67 Helena(COLUMN)67(COLUMN)36 Honolulu(COLUMN)89(COLUMN)79 Houston(COLUMN)87(COLUMN)79 Indianapolis(COLUMN)90(COLUMN)72 Jackson, Miss.(COLUMN)91(COLUMN)73 Jacksonville(COLUMN)88(COLUMN)75 Kansas City(COLUMN)90(COLUMN)64 Las Vegas(COLUMN)96(COLUMN)68 Little Rock(COLUMN)87(COLUMN)70 Los Angeles(COLUMN)82(COLUMN)69 Louisville(COLUMN)88(COLUMN)73 Memphis(COLUMN)93(COLUMN)75 Miami Beach(COLUMN)85(COLUMN)74 Midland(COLUMN)100(COLUMN)73 Milwaukee(COLUMN)89(COLUMN)75 Mpls.-St. Paul(COLUMN)88(COLUMN)63 Nashville(COLUMN)90(COLUMN)71 New Orleans(COLUMN)91(COLUMN)78 New York(COLUMN)82(COLUMN)71 Norfolk(COLUMN)86(COLUMN)69 North Platte(COLUMN)76(COLUMN)47 Oklahoma City(COLUMN)93(COLUMN)73 Omaha(COLUMN)87(COLUMN)62 Orlando(COLUMN)82(COLUMN)74 Philadelphia(COLUMN)84(COLUMN)69 Phoenix(COLUMN)100(COLUMN)79 Pittsburgh(COLUMN)86(COLUMN)68 Portland, Me.(COLUMN)77(COLUMN)62 Portland, Ore.(COLUMN)69(COLUMN)58 Providence(COLUMN)80(COLUMN)68 Raleigh(COLUMN)86(COLUMN)66 Rapid City(COLUMN)68(COLUMN)44 Reno(COLUMN)85(COLUMN)44 Richmond(COLUMN)89(COLUMN)67 St. Louis(COLUMN)91(COLUMN)76 St. Prbg-Tampa(COLUMN)88(COLUMN)76 Salt Lake City(COLUMN)69(COLUMN)56 San Antonio(COLUMN)92(COLUMN)75 San Diego(COLUMN)74(COLUMN)68 San Francisco(COLUMN)75(COLUMN)62 San Juan, P.R.(COLUMN)87(COLUMN)76 St. Ste. Marie(COLUMN)83(COLUMN)71 Seattle(COLUMN)67(COLUMN)57 Shreveport(COLUMN)92(COLUMN)69 Sioux Falls(COLUMN)82(COLUMN)56 Spokane(COLUMN)67(COLUMN)48 Syracuse(COLUMN)84(COLUMN)72 Topeka(COLUMN)92(COLUMN)66 Tucson(COLUMN)94(COLUMN)74 Tulsa(COLUMN)94(COLUMN)76 Washington(COLUMN)87(COLUMN)70 Wichita(COLUMN)92(COLUMN)66(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)T. Aberdeen(COLUMN)rain(COLUMN)1 p.m.(COLUMN)55 Amsterdam(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)63 Ankara(COLUMN)clear(COLUMN)3 p.m.(COLUMN)75 Athens(COLUMN)clear(COLUMN)2 p.m.(COLUMN)86 Auckland(COLUMN)cloudy(COLUMN)midnight(COLUMN)-9 Berlin(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)73 Birmingham(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)59 Brussels(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)61 Cairo(COLUMN)clear(COLUMN)2 p.m.(COLUMN)91 Casablanca(COLUMN)pt. cldy(COLUMN)noon(COLUMN)72 Copenhagen(COLUMN)clear(COLUMN)1 p.m.(COLUMN)66 Dublin(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)57 Geneva(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)63 Hong Kong(COLUMN)pt. cldy(COLUMN)8 p.m.(COLUMN)84 Lisbon(COLUMN)clear(COLUMN)noon(COLUMN)72 London(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)72 Madrid(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)70 Malta(COLUMN)clear(COLUMN)1 p.m.(COLUMN)82 Manila(COLUMN)pt. cldy(COLUMN)8 p.m.(COLUMN)81 Moscow(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)72 New Delhi(COLUMN)cloudy(COLUMN)5 p.m.(COLUMN)86 Nice(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)70 Oslo(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)59 Paris(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)63 Peking(COLUMN)clear(COLUMN)8 p.m.(COLUMN)77 Rome(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)82 Saigon(COLUMN)clear(COLUMN)8 p.m.(COLUMN)86 Sofia(COLUMN)clear(COLUMN)2 p.m.(COLUMN)79 Stockholm(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)57 Sydney(COLUMN)cloudy(COLUMN)10 p.m.(COLUMN)57 Tel Aviv(COLUMN)clear(COLUMN)2 p.m.(COLUMN)88 Tokyo(COLUMN)cloudy(COLUMN)9 p.m.(COLUMN)79 Tunis(COLUMN)clear(COLUMN)1 p.m.(COLUMN)91 Vienna(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)68 Warsaw(COLUMN)rain(COLUMN)1 p.m.(COLUMN)59(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulco(COLUMN)pt. cldy(COLUMN)90(COLUMN)79 Barbados(COLUMN)pt. cldy(COLUMN)84(COLUMN)79 Bermuda(COLUMN)pt. cldy(COLUMN)85(COLUMN)79 Calgary(COLUMN)clear(COLUMN)61(COLUMN)37 Culiacan(COLUMN)pt. cldy(COLUMN)91(COLUMN)77 Edmonton(COLUMN)clear(COLUMN)64(COLUMN)36 Havana(COLUMN)pt. cldy(COLUMN)86(COLUMN)73 Kingston(COLUMN)pt. cldy(COLUMN)90(COLUMN)79 Mexico City(COLUMN)pt. cldy(COLUMN)77(COLUMN)59 Monterrey(COLUMN)pt. cldy(COLUMN)97(COLUMN)73 Montreal(COLUMN)pt. cldy(COLUMN)97(COLUMN)61 Montreal(COLUMN)clear(COLUMN)81(COLUMN)72 Nassau(COLUMN)cloudy(COLUMN)88(COLUMN)73 Ottawa(COLUMN)clear(COLUMN)81(COLUMN)72 Regina(COLUMN)clear(COLUMN)66(COLUMN)34 St. Kitts(COLUMN)pt. cldy(COLUMN)90(COLUMN)78 St. Thomas(COLUMN)pt. cldy(COLUMN)88(COLUMN)79 Toronto(COLUMN)clear(COLUMN)86(COLUMN)73 Vancouver(COLUMN)rain(COLUMN)68(COLUMN)55 Veracruz(COLUMN)pt. cldy(COLUMN)91(COLUMN)76 Winnipeg(COLUMN)cloudy(COLUMN)70(COLUMN)55(END TABLE)