Sandaysoft

Ray, since April 2009 I not recorded an air frost. In open areas especially if its low lying I would because other areas get frost, but a hilly forest does surround my suburb to the west and northwest, on the other side in a large valley they get frost and gets much colder. I am also on a bit of hill so unlike other low lying areas which get frost I am lucky to miss out. Put it this way Brisbane is 8m ASL and I am 76m ASL over a distance of 12km.

We do sometimes get a very light frost, but its been years since that happened. Yesterday we got a fraction of ice crystals but not frost. I would think the last time we got a frost was in July 2008 which I would esimate as a air temperature of 0.3, so thats not an air frost,and also similar in July 2007, I would estimate a similar temp to 0.7 in August 2008. In 2000/2002 and 2004/2005 I would estimate around 0.0 so I would think we got a light frost. This is only a estimate before I measured it based on what the offical Bureau station in Brisbane has recorded.

But I do enjoy this weather while it lasts because the summer and its heat, humidity, storms, rain and dry spells is not something to look forward to, but I am sure others have its worst. I would estimate Yesterday felt like -1. I am very lucky to not get frost and the damage it does. Its a pity for you that you have not had much of a summer as I seen with the Games, your summer max temperature is no higher than my winter max.

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Regards, Matt of Brisbane, Australia
Web Site: http://www.localweatherdata.0glo.com

Matt,

It's a pity you can't record grass temperature because you would certainly get a negative recording despite your higher altitude.

Yes, our max temps are poor compared to many but at least it allows us to work outside without discomfort. At 53N our climate will be very different to one close to the Tropic of Capricorn but with the proximity of the North Atlantic our climate is mostly dominated by a maritime airstream. Hot summers and very cold winters usually have an air stream sourced from the east - the mainland of Europe.

Vive la difference!

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Cheers,
Ray, Cheshire.

Ray, I could measure grass temperature, which is something that is overlooked. I am not sure how I would do this. I can’t measure it with my La Crosse as extra sensors can’t be used and as far as I understand the La Crosse sensor can’t get wet.

I could add it to my manual records using a mercury thermometer (but I would have to protect from the sun) as I use a sensor from another station to get the overnight because the main station used with Cumulus and my manual records is sited near the wind and rain sensors as good wind readings are not possible at the location of the extra sensor for the overnight reading.

My La Crosse (about 10 months old) used with Cumulus has been trouble and at some point in the future I wish to upgrade most likely to a Davis in which I can site the temperature readings closer to the best spot for the wind readings and so get good overnight readings without having a use the extra sensor and having to build a shelter for my La Crosse, which is beyond me to get good overnight readings, but still have trouble with my station. I have been disappointed with this station with crazy -6 etc. spikes and garbage readings making keeping the Cumulus files clean an annoying battle, lost connection in cold mornings which for three hours yesterday and again this morning (even moving the receiver 2 metres from the outdoor unit it failed to pick up the signal) and poor wind readings with much smaller wind cups than I expected.

But with cold mornings there would be many days that won’t be below 0 at ground level, normally it gets down to 2 to 3 at the lowest and only sometimes to 1 and the odd below 0 to around 0. Your max temps for summer seem alright, max temps here in winter are warm but not too high, but I guess your winter would not be as good but as least you don’t get hard heatwaves like here. But there is a big difference in the climates here and over your way.

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Regards, Matt of Brisbane, Australia
Web Site: http://www.localweatherdata.0glo.com

Matt,

Measuring grass temperature requires an additional sensor which many stations cannot support. Davis do one but as with all their kit it is expensive. The alternative is to use a max/min thermometer and take a manual reading each day since only a min is really used. Not ideal but at least it's cheap.

Davis kit is expensive worldwide outside the US but its reliability is excellent. No spikes and a very good radiation screen. I bought the wireless anemometer transmitter to allow me to place the ane up on the chimney stack with the ISS in the back garden. Although Davis show them all together on the ISS it's not an ideal setup unless you live in the wilderness with no trees or hills close.

Consider the Davis an investment rather than a luxury. Over time it can work out cheaper than lesser stations simply because of its longevity.

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Cheers,
Ray, Cheshire.

Hi Ray, Thanks for your comments.
I will mostly likely use a mercury thermometer and add it to my manual records, if I had an extra weather station to hand I would but I would need to protect the sensor from the sun and rain. It is a little annoying that extra sensors are not a option in many stations. I just wondering whether the sunshine on the mercury thermometer all the time would damage it or could it stand the sunshine. I would think getting it wet would not do any harm.

And with the Davis I agree with your comments, which I will mostly likely upgrade to in the future. Its been a far bit of a battle with my station especially editing the Cumlulus files on a regular basis to keep it working well. And only can get overnight figures with my manual records but my Cumulus can't reflect that. I will certainly get better readings with Cumulus when I do upgrade. Its is expensive, I have reading up about the Davis lately, I think it is worth it because like you said its a investement that will last longer. I would use the transmitter kit with the wind sensor by the house and put the ISS over grass.

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Regards, Matt of Brisbane, Australia
Web Site: http://www.localweatherdata.0glo.com

Hi Matt,

In between watching an amazing evening at the Olympics I tried to find a grass thermometer but couldn't. Odd.

You don't need anything fancy. Just a simple analogue min/max thermometer and a way to support it a couple of inches (cm) above the grass. Thermometers can usually survive bright sunshine and rain.

You won't need to edit Cumulus data very often with a Davis. Amazingly reliable. And your plan to add a second trasmitter for the anemometer is ideal for accurate wind measurements. 33ft (10 mtr) up is the ideal placement.

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Cheers,
Ray, Cheshire.

Thanks Ray for your comments, its most helpful.

I do have a min/max mercury thermometer, but its done its day, I only use for testing. I can easily buy one to use for the grass temperature. My only concern was the sun but I think I should be right. I did put it out this morning to test it, on the grass but maybe it was colder earlier in the night, but I am concerned that in the back garden it gets too warm with surrounding house, plants and fence but is a few metres away.

With my newer La Crosse, for three days in a row to today, I have got lost connection and flatlining for a few hours each morning which is so annoying. I have found unless the batteries in the indoor unit is really fresh in cool mornings of 2 degree or lower it can't pick up a signal even if brough outside. I so sick of editing the Cumlus files that no spikes with the Davis would be great. With the Davis it will allow the overnight figures to be reflected in Cumulus, something that is currently not possible. And the wind readings in the newer La Crosse have been disappointing as the small wind cups make readings too high or too low for much of the time. My first La Crosse gives much better wind readings but has no pc connection.

I did consider only using one of the two La Crosse units but because of the bad wind readings and spikes I have to continue to use both La Crosse units for my recordings but the older one still works fine after 2 and a half years. I will mount the Davis ane a bit higher than at the moment which is at eaves level, but can't do it too high because only for security I don't want it to attract attention to neighbours, but my readings will be much better.

But has been very nice of you to offer your thoughts and advice with the grass readings and the Davis. And the games have been good to watch.

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Regards, Matt of Brisbane, Australia
Web Site: http://www.localweatherdata.0glo.com

Hi Matt,

I can hear your frustration with your La Crosse. Everything is built to a price and you generally get what you pay for. But not everyone wants or can afford a Davis. I certainly ummed and aahed for a long time before taking the plunge. But my experience with a modest Oregon Scientific outdoor thermometer and its inability to keep a consistent signal with the console persuaded me to go with Davis which has a very robust signal.

I wouldn't worry about how warm your garden gets. You're only recording the min grass temp. And as far as your La Crosse placement is concerned very few of us have perfect surroundings. My own temps are about 1C higher than nearby Manchester Airport but gardens are generally warmer than open-spaced airports so I don't worry.

Once you get a Davis you'll be as happy as a pig in muck!

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Cheers,
Ray, Cheshire.

Thanks so much Ray for your comments, you do get what you pay for, but the Davis does have a bigger cost to it, but it would be worth it. In August last year I was looking into getting a station to use with Cumulus to go a bit further, and I did consider a Davis but I thought it was bit too expensive. So I bought a cheaper one as my other La Crosse had been good but it was not meant to be. After three years I not sure I want to buy another cheap one, I rather invest a bit more for less trouble and better readings.

With the current recordings my La Crosse placement is under cover by the house which is 2 to 4C higher than in the open as my extra sensor records but is not reflected in the Cumulus records. But the garden reading are not perfect and I accept that, I only though it may not warrant measuring the grass temp, but I will give it a go and anyway it my grass I am measuring.

But thanks for all your help, it is very useful.

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Regards, Matt of Brisbane, Australia
Web Site: http://www.localweatherdata.0glo.com

Hi Matt,

Any chance you can upload a photo of your garden? Placement of temperature sensors near a house will affect the reading irrespective of the quality of the unit.

Ideally, you want it as far from areas of heat as is possible / practical. So avoid patios, north-facing walls and such like. Position the ISS over grass if you can. The radiation shield is first class but it can be improved with a Daytime FARS. This is a solar-powered fan that only turns when the sun shines on the panel. Stops any build-up of heat inside the radion shields. It's desirable but not essential.

Very few have perfect surroundings but just remember you're recording conditions in YOUR garden and not the local airport.

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Cheers,
Ray, Cheshire.

Hi Ray, I will send you a PM later today with more info and a photo of the garden. Thanks very much of your help.

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Regards, Matt of Brisbane, Australia
Web Site: http://www.localweatherdata.0glo.com

With my previous old Oregon WM918

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Laurent

Laurent,

I remember that summer well. It was a scorcher in England too but I didn't have a weather station. The UK max that summer was 38.5 on 10 August. Full details here. http://www.metoffice.gov.uk/climate/uk/ ... temps.html

Matt,

Look forward to it.

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Cheers,
Ray, Cheshire.

Upcoming a heat wave in The Netherlands for sunday 35 C is expected over here 34,7 C july 9th 2010 was my highest temperature it will be close, anyway I don't like these temperatures I think I'm going to sleep in the cellar

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Ron



Apeldoorn, The Netherlands

Only had my weather station since December 2009, but my oldest record is from February 2010, with a Highest Hourly Rainfall of 15.3mm

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Richard