Cumulus Support

Hi,
Another newbie question!!!
Had my weather station for a few weeks now and still getting used to it.
Noticed the past few days i have been getting a temperature spike at around midday to 1pm.
I assumed it was getting direct sunlight, so this morning i moved it to a shady location.
But the spike is still there?
Can anyone shed any light on this for me??

It may pick up heat if near (30cm) to a heated surface or picking up heated air. Can you do a screen shot of the temp graph in the normal graph mode so that we can see what else is happening in the other graphs.

Is this the one you meant??

The station is mounted on the handrails on the deck. Looking around other posts, maybe it is getting radiated heat off the deck surface. Its a rented house so i cant put the station on a larger pole as the landlord wont let me make a few screw holes!! Its in the best location i can get it for now anyway.

I see you are getting very little wind and direction, totally understandable, if I assume those gauges are on the deck as well?
I don't see a spike in the temp. So to explain the sudden rise in temps (not really a spike, I normally refer them to when there's a signal prob and it spits out a funny number), you may be getting heated up air that is being read. It then may be being blown away when the winds pick up?
Also, I see you had rain a few days back. Do a Select-A-Graph that combines temp (out), wind (av and peak) and humidity. When rains come and can bring cool winds to knock the temp down, and you'll notice a jump in humidity (if it's not already high).

I would see if you could take the temp sensor off the pole and move the pole with wind meters and place on the roof. Try and find some existing screws on the roof facia and use them to screw a clamp onto the pole. If not, you could place the pole on a plank of wood and use existing roof bolts to screw the plank down (if you have bolts?), and secure the pole to the plank using 3 or 4 support wires (picture frame wire if you like). This will improve your wind data.

For the temp gauge, does the rail get hot? Is the guage now in complete shade all day (or when the spikes occure)? If that's all OK, then perhaps it is picking up deck heat. Find a place that's nice to sit all day. That's the place to put it. That spot is probably back from the deck and not near the ceiling or the floor. Just don't trip on the cables. See if any of this is doable. It seems your in a difficult spot, more so since your renting. Any other spot around the building?

Awesome advise. I will take a pic of the setup tomorrow as it is dark now.

I do get good wind data when its windy. I used to live in the UK and get wind all the time, but here in Canada its either blowing a gale or still air!! The area the house is in is very sheltered by trees anyway but even in open areas round here the wind is either on or off!!

I moved the temperature sensor yesterday morning, before the spike at 12 noon to 1pm. After your wise words i am sure its a combination of sunlight on the deck and light winds. If the leads are long enough i am going to put the sensor under the deck tomorrow morning. (its a raised deck 5ft off the floor)

Thanks again for your advice and assistance. Will post the other pic tomorrow.

I see you had the wind and humidity go up around the time the temp droped. My guess is that you had or nearly had rain at those times. Can you do a coresponding graph of just the rain rate?
Also, I found that before storms hit where I am in the tropics that the wind will go towards where the storm is coming from 1/2 hour or more before rain arives, then does a 180 spin 5-15 minutes before the storm hits. That initial wind that travels toward the storm, is that bringing in hot air from somewhere? Or perhaps you have that still moment before the storm, when the sun is hot, and it holds the heated air from your deck?
Have fun sorting that out!

Thanks for the further advice, but, it hasnt rained in those 4 days, nor has there been a cloud in the sky.

Its been wonderful weather in fact, blue sky and sunshine.

Are you using the spike removal feature built into Cumulus?

I had almost the same problem as you with my WS1090. I had my station for a few weeks then I started getting spikes randomly. (My Wind, Temp, and Humidity sensors would randomly just read GIANT drops or rises, (ex calm wind to 97mph gust, 70% humidity, dropping to 15%, and temperature from 60F to 10F) and it would happen when the station lost contact with the sensor, usually overnight around 1am-3am but not every day. I would get the odd data, then anywhere from 2-15 "Lost Sensor Contact" messages, then I would get "normal" data back. After going through my house and trying to find out what could be causing interference, moving sensor closer, and nothing working I just gave up. Figured it's the sensor/transmitter itself.

Either way using the spike removal feature fixed everything for me. (Configuration >> Calibration).
My settings are 11.1C, 9.0m/s, 9.0m/s, 10.0%, 5.1mb, 254.0mm/hr, 127.0mm and it seems to be holding fine for me. I makes Cumulus just ignore any data that is xx (Whatever unit you put in) off from the last reading. I also have a "Deck" setup and get low wind spikes, so 9.0m/s (20mph) is good for me, since I get getting odd 25mph spikes with no wind at all so it had to be lower than that.

The spike removal facility isn't going to help here, because as Michael points out, these aren't "spikes" (sudden changes in reading) as such.