If you plan to hike/climb to Camp Muir, the NPS has issued a press release about the conditions on the snowfield to Camp Muir, see news release (PDF) and cited below along with the Get Your Bearings (PDF) release.
The NPS press read as follows:
"The annual snowpack on the Muir Snowfield has melted out unusually early this year. This has exposed bare glacier ice and crevasses on the route from Paradise to Camp Muir. From about 8,200 feet and up on this route, which is popular for climbers and day hikers to Camp Muir, the terrain often exceeds a 25-30 degree slope. The steepness, coupled with the exposed glacier ice, make for extremely slippery and hazardous walking. The glacier ice is not kind to exposed skin if you should fall and slide on it. There have been numerous cases this year of slips that have caused fairly severe abrasions. Also this year, the exposed ice from 9,500 feet to 10,100 feet has opened up crevasses that require skill and care in safely picking out circuitous routes which avoid the open cracks in the ice. Over the years, people have found themselves injured by falling in the crevasses or left dangling above them.
The trek to Camp Muir can be an enjoyable hike in these conditions if good judgment and proper precautions are taken. Please follow these helpful hints for safe hiking up to Camp Muir:
• Get the latest route conditions at the Climbing Information Center in Paradise (360-569-6009) or the Wilderness Information Center in Longmire (360-569-HIKE, 360-569-4453)
• Carry and use crampons and an ice axe
• Cover all skin with durable full-length pants and long-sleeve shirts
• Download the Muir Route Bearing Sheet (Get Your Bearings - PDF)
• Carry a map, GPS, and compass, and know how to use them. Track your route on the way up, trackback on the descent
• Travel to Camp Muir with someone. If you should fall in a crevasse, there will be someone to help you or go for help
• The only anchors that work in the glacier ice are ice screws, should you choose to belay over the crevasses with a short section of rope
• Weather can deteriorate at any time. Get up-to-date forecasts and prepare for cold, wet weather"
You can check the NPS News Web page for the latest information and reports.