Rainier OR 10Day Weather Forecast The Weather Channel Longview , Washington State, the weather is pleasant and enjoyable all year round. Whether you are exploring the vibrant downtown area or exploring the surrounding picturesque landscapes, you can expect comfortable weather throughout your stay. From hot summers to cool autumns, and from gentle winters to refreshing springs, Longview, Washington offers a plethora of open-air activities for adventure seekers. So pack your sunscreen and umbrella, as Longview, Washington's weather is ready to delight you with its changeful and captivating conditions.