Currently, soil temperatures at a 4" depth under bare soil are in the low 50s in western NE to the upper 50s and low 60s in the southeast. Soil temperatures, especially under bare soil can fluctuate quite a bit from day to day AND from morning to afternoon.
Current soil temperatures can be found at the Nebraska Mesonet (mesonet.unl.edu), which is part of the Nebraska State Climate Office or can be found at CropWatch (cropwatch.unl.edu). These soil temperatures are the average of the entire day, so take that into account, if you are taking your own soil temperatures at a single point during the day. There can be quite a difference between the two.
With harvest quickly winding down, you may want to get moving on anhydrous applications, but the forecast for the next 10-14 days does not look like soil temperatures will drop very fast. The Climate Prediction Center 8-14 day outlook has a 70% probability for Nebraska having above normal temperatures for that time period. The normal daily high to start November is in the upper 50s.
*Anhydrous ammonia applications in the fall are not recommended for coarse textured soils due to leaching potential or areas with other application restrictions.