Washington: Today - Partly cloudy, high in 80s, low near 70. Chance of rain 10 per cent through tonight. Monday - Partly cloudy, high in 80s.

Maryland: Today - Partly cloudy, highs in 80s, lows in 60s. Monday - Partly cloudy, highs in 80s.

Virginia: Today - Partly cloudy, highs in 80s, lows in 70s. Chance of afternoon and evening showers. Monday - Partly cloudy with chance of afternoon and evening rain, highs in 80s.

Lower Potomac and Chesapeake Bay: Today - Partly cloudy skies with good to fair visibility through tonight.Winds should be northeasterly at up to 10 knots becoming variable at about 5 knots tonight.

Extended Area Outlook: For Tuesday through Thursday - Humid through period with chance of afternoon or evening showers in mountains through Wednesday and throughout area Thursday. Highs should average in mid 80s to mid 90s, lows in 60s to mid 70s. Washington's normal temperature range for this time of year is from 88 to 69.

Atlantic Ocean Beaches from Cape May through Maryland: Today and Monday - Partly cloudy, highs near 80. Water temperatures should be in low to mid 70s.

Atlantic Ocean Beach from Cape Hatteras through Virginia: Today and Monday - Partly cloudy with chance of afternoon and evening showers, highs in 80s. Water temperatures should be in mid to upper 70s.

West Virginia: Today - Partly cloudy, highs in upper 70s to mid 80s, lows in 60s. Monday - Partly cloudy, highs in upper 70s to mid 80s.

The National Weather Forecast for Today - Showers and thundershowers will be scattered from the southern Atlantic states west to the lower Mississippi Valley, scattered thundershowers will be moving from the northern Plains into the upper Mississippi Valley. Showers will be scattered over the northern Rockies. Other than the southern Appalachian Mountains and the northern Plains, it will be mostly sunny across the nation. Ninety degree readings will be confined to the southern quarter of the nation, the high Plains and interior California. One hundred plus temperatures are expected only in the desert southwest. It will continue mild in the Pacific Northwest and the northern Plateau with readings only in the 70s. It will also be on the mild side over eastern New England and in the upper Ohio Valley. Elsewhere, it will be seasonably warm.

ALMANAC DATA FOR Sunday, July 10, 1977: Sun rises 5:51 a.m., sets 8:35 p.m.; moon rises 1:47 a.m. sets 3:45 p.m. Tides: High 4:21 a.m. and 4:20 p.m., low 11:13 a.m. and 11:22 p.m. High and low tides at the following locations can be obtained 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 3 p.m. period was 125 for the pollutant, photochemical oxidants. Index values between 100 and 249 indicate very unhealthy air quality. When the index exceeds 100 the air becomes hazardous and persons with lung, heart and eye problems should restrict their activity. The forecast for today indicates the air quality will remain about the same.

The National Weather Service forecasts that the Potomac River stage at Little Falls will remain near 2.8 feet today. Local Temp., Humidity(TABLE) Time(COLUMN)T.(COLUMN)H. 12 mid. 80(COLUMN)85 1 a.m.(COLUMN)79(COLUMN)88 2 a.m.(COLUMN)78(COLUMN)94 3 a.m.(COLUMN)79(COLUMN)91 4 a.m.(COLUMN)79(COLUMN)88 5 a.m.(COLUMN)78(COLUMN)91 6 a.m.(COLUMN)78(COLUMN)91 7 a.m.(COLUMN)79(COLUMN)88 8 a.m.(COLUMN)80(COLUMN)85 9 a.m.(COLUMN)84(COLUMN)75 10 a.m.(COLUMN)86(COLUMN)68 11 a.m.(COLUMN)77(COLUMN)90 12 noon(COLUMN)80(COLUMN)82 1 p.m.(COLUMN)81(COLUMN)82 2 p.m.(COLUMN)87(COLUMN)68 3 p.m.(COLUMN)89(COLUMN)64 4 p.m.(COLUMN)89(COLUMN)64 5 p.m.(COLUMN)90(COLUMN)62(END TABLE) Temperatures ending 8 a.m. (EDT) Yesterday(TABLE) City(COLUMN)H.(COLUMN)L. Albany(COLUMN)77(COLUMN)61 Albuquerque(COLUMN)89(COLUMN)60 Amarillo(COLUMN)86(COLUMN)63 Anchorage(COLUMN)68(COLUMN)55 Asheville(COLUMN)92(COLUMN)68 Atlanta(COLUMN)98(COLUMN)68 Atlantic City(COLUMN)87(COLUMN)72 Austin(COLUMN)95(COLUMN)73 Baltimore(COLUMN)95(COLUMN)73 Billings(COLUMN)83(COLUMN)57 Birmingham(COLUMN)104(COLUMN)71 Bismarck(COLUMN)72(COLUMN)50 Boise(COLUMN)96(COLUMN)54 Boston(COLUMN)69(COLUMN)62 Brownsville(COLUMN)93(COLUMN)71 Buffalo(COLUMN)73(COLUMN)65 Burlington, Vt.(COLUMN)66(COLUMN)60 Casper(COLUMN)86(COLUMN)50 Charleston, S.C.(COLUMN)98(COLUMN)80 Chlstn., W.Va.(COLUMN)94(COLUMN)71 Charlotte, N.C.(COLUMN)100(COLUMN)75 Cheyenne(COLUMN)77(COLUMN)54 Chicago(COLUMN)87(COLUMN)69 Cincinnati(COLUMN)91(COLUMN)72 Cleveland(COLUMN)78(COLUMN)63 Columbia, S.C.(COLUMN)105(COLUMN)72 Columbus, Ohio(COLUMN)89(COLUMN)73 Dal.-FT. Worth(COLUMN)100(COLUMN)72 Dayton(COLUMN)91(COLUMN)72 Denver(COLUMN)81(COLUMN)63 Des Moines(COLUMN)88(COLUMN)62 Detroit(COLUMN)90(COLUMN)68 Duluth(COLUMN)70(COLUMN)47 El Paso(COLUMN)98(COLUMN)63 Fairbanks(COLUMN)81(COLUMN)52 Fargo(COLUMN)70(COLUMN)49 Flagstaff(COLUMN)87(COLUMN)47 Great Falls(COLUMN)84(COLUMN)57 Hartford(COLUMN)76(COLUMN)65 Helena(COLUMN)82(COLUMN)52 Honolulu(COLUMN)87(COLUMN)75 Houston(COLUMN)94(COLUMN)79 Indianapolis(COLUMN)89(COLUMN)70 Jackson, Miss.(COLUMN)98(COLUMN)73 Jacksonville(COLUMN)97(COLUMN)72 Juneau(COLUMN)76(COLUMN)52 Kansas City(COLUMN)86(COLUMN)64 Las Vegas(COLUMN)107(COLUMN)78 Little Rock(COLUMN)100(COLUMN)72 Los Angeles(COLUMN)81(COLUMN)62 Louisville(COLUMN)95(COLUMN)71 Memphis(COLUMN)98(COLUMN)79 Miami Beach(COLUMN)85(COLUMN)81 Midland(COLUMN)95(COLUMN)69 Milwaukee(COLUMN)85(COLUMN)59 Mpls.-St. Paul(COLUMN)78(COLUMN)55 Nashville(COLUMN)99(COLUMN)75 New Orleans(COLUMN)94(COLUMN)76 New York(COLUMN)88(COLUMN)70 Norfolk(COLUMN)99(COLUMN)75 North Platte(COLUMN)81(COLUMN)60 Oklahoma City(COLUMN)89(COLUMN)72 Omaha(COLUMN)87(COLUMN)59 Orlando(COLUMN)93(COLUMN)71 Philadelphia(COLUMN)90(COLUMN)74 Phoenix(COLUMN)110(COLUMN)86 Pittsburgh(COLUMN)83(COLUMN)66 Portland, Me.(COLUMN)67(COLUMN)56 Portland, Ore.(COLUMN)77(COLUMN)58 Providence(COLUMN)71(COLUMN)62 Raleigh(COLUMN)103(COLUMN)72 Rapid City(COLUMN)78(COLUMN)57 Reno(COLUMN)90(COLUMN)46 Richmond(COLUMN)101(COLUMN)72 St. Louis(COLUMN)90(COLUMN)71 St. Prbg.-Tampa(COLUMN)91(COLUMN)74 Salt Lake City(COLUMN)95(COLUMN)71 San Antonio(COLUMN)92(COLUMN)75 San Diego(COLUMN)74(COLUMN)63 San Francisco(COLUMN)63(COLUMN)52 San Juan, PR.(COLUMN)88(COLUMN)76 St. Ste. Marie(COLUMN)76(COLUMN)46 Seattle(COLUMN)73(COLUMN)56 Shreveport(COLUMN)97(COLUMN)73 Sioux Falls(COLUMN)81(COLUMN)58 Spokane(COLUMN)86(COLUMN)60 Syracuse(COLUMN)72(COLUMN)62 Topeka(COLUMN)88(COLUMN)64 Tucson(COLUMN)104(COLUMN)82 Tulsa(COLUMN)89(COLUMN)72 Washington(COLUMN)96(COLUMN)55 Wichita(COLUMN)88(COLUMN)69(END TABLE) Temperatures Abroad Yesterday(TABLE) City(COLUMN)Weather(COLUMN)Time(COLUMN)Temp. Aberdeen(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)57 Amsterdam(COLUMN)rain(COLUMN)1 p.m.(COLUMN)68 Ankara(COLUMN)clear(COLUMN)3 p.m.(COLUMN)82 Athens(COLUMN)clear(COLUMN)2 p.m.(COLUMN)86 Auckland(COLUMN)clear(COLUMN)midnight(COLUMN)45 Berlin(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)66 Birmingham(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)63 Brussels(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)66 Cairo(COLUMN)clear(COLUMN)2 p.m.(COLUMN)93 Casablance(COLUMN)pt. cldy(COLUMN)noon(COLUMN)72 Copenhagen(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)68 Dublim(COLUMN)clear(COLUMN)1 p.m.(COLUMN)66 Geneva(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)73 Hong Kong(COLUMN)clear(COLUMN)8 p.m.(COLUMN)84 Lisbon(COLUMN)clear(COLUMN)noon(COLUMN)70 London(COLUMN)clear(COLUMN)1 p.m.(COLUMN)68 Madrid(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)81 Malta(COLUMN)clear(COLUMN)1 p.m.(COLUMN)91 Manila(COLUMN)rain(COLUMN)8 p.m.(COLUMN)77 Moscow(COLUMN)cloudy(COLUMN)3 p.m.(COLUMN)68 New Delhi(COLUMN)rain(COLUMN)5 p.m.(COLUMN)81 Nice(COLUMN)storm(COLUMN)1 p.m.(COLUMN)73 Oslo(COLUMN)clear(COLUMN)1 p.m.(COLUMN)79 Paris(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)72 Peking(COLUMN)clear(COLUMN)8 p.m.(COLUMN)82 Rome(COLUMN)clear(COLUMN)1 p.m.(COLUMN)81 Saigon(COLUMN)cloudy(COLUMN)8 p.m.(COLUMN)88 Sofia(COLUMN)clear(COLUMN)2 p.m.(COLUMN)86 Stockholm(COLUMN)clear(COLUMN)1 p.m.(COLUMN)73 Sydney(COLUMN)clear(COLUMN)10 p.m.(COLUMN)54 Tel Aviv(COLUMN)clear(COLUMN)2 p.m.(COLUMN)86 Tokyo(COLUMN)clear(COLUMN)9 p.m.(COLUMN)75 Tunis(COLUMN)clear(COLUMN)1 p.m.(COLUMN)82 Vienna(COLUMN)cloudy(COLUMN)1 p.m.(COLUMN)70 Warsaw(COLUMN)pt. cldy(COLUMN)1 p.m.(COLUMN)70(END TABLE) Temperatures (Western Hemisphere)(TABLE) City(COLUMN)Weather(COLUMN)High(COLUMN)Low Acapulco(COLUMN)fair(COLUMN)91(COLUMN)77 Barbados(COLUMN)fair(COLUMN)86(COLUMN)79 Bermuda(COLUMN)cloudy(COLUMN)85(COLUMN)78 Bogota(COLUMN)pt. cldy(COLUMN)66(COLUMN)42 Havana(COLUMN)sunny(COLUMN)91(COLUMN)73 Kingston(COLUMN)sunny(COLUMN)90(COLUMN)77 Montego Bay(COLUMN)sunny(COLUMN)88(COLUMN)75 Mexico City(COLUMN)cloudy(COLUMN)72(COLUMN)53 Monterrey(COLUMN)sunny(COLUMN)95(COLUMN)69 Nassau(COLUMN)fair(COLUMN)90(COLUMN)73 St. Kitts(COLUMN)sunny(COLUMN)89(COLUMN)78 Veracruz(COLUMN)cloudy(COLUMN)88(COLUMN)75(END TABLE)