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October 2019

Congratulations to Heng Suli who was recently conferred the Master of Social Science degree for her thesis “Using thermal walks to examine pedestrian’s thermal (dis)comfort when transiting across indoor, semi-outdoor and outdoor thermal environments in Singapore’s equatorial climate”. We wish her all the best in her future.

Latest news

August 2023

Simple beats complex: Well-evaluated numerical urban climate models can provide simulations of canopy layer air temperature and urban heat islands in areas which lack observations. Many of these models, however, need significant computational resources, and the complex parameterizations involved require expertise to carry out the simulations. We have developed a simple statistical model which can predict the maximum urban heat island intensity under specific weather conditions based on the urban fraction and height-to-width ratio of a neighbourhood of interest and four weather variables measured at a reference location. Non-dimensional analysis is used to derive the semi-empirical equation. The approach works best when conditions for nighttime maximum heat island development are 'ideal’ (dry, calm and clear). Under these conditions, model-observation error metrics are better than those obtained using a more complicated numerical urban climate model.


The image on the right shows the mean nighttime urban heat island map for Singapore for 'UHI_maximum’ using the semi-empirical statistical model applied to 300 m gridded morphological and land cover data for ‘ideal' conditions. The highest individual grid-cell modelled UHI_max intensities reach 6.0 ºC (located in the CBD), and the most frequently occurring UHI_max values are between 4.5-5 ºC. The area-weighted UHI_max intensity considering all built-up areas on Singapore main island is 2.64 ºC - this can be interpreted as the nighttime city-wide average air temperature increment caused by the presence of the city under ‘ideal’ conditions.

Reference: Sanchez B, Roth M, Patel P and Simón-Moral A, 2023. Spatial and temporal characteristics of near-surface air temperature across local climate zones in a tropical city. Sustainability 2023, 15, 12834. (


July 2023

Congratulations to Urban Climate Lab alumnus Winston Chow (class of 2004) for being elected as a IPCC Developing Country Co-Chair, contribute to Working Group II, which focuses on climate change impact and adaptation measures as part of its seventh assessment report cycle (

November 2022

It took many years, but finally published, one of the most comprehensive UHI studies in a (sub)tropical city: Roth M, Sanchez B, Li R and Velasco E, 2022. Spatial and temporal characteristics of near-surface air temperature across local climate zones in a tropical city. International Journal of Climatology ( 


In situ observations reveal significant near-surface air temperature variability across tropical Singapore. Differences between built type neighbourhoods and a reference ‘rural’ background site vary according to local climate zone (LCZ), weather and season. Overall highest daytime temperatures are observed in neighbourhoods characterized by low-rise buildings, high percentage of impervious surfaces and a lack of vegetation, where heat exposure is most severe.


One of the most significant findings is: "The data suggest an extra 1.0–1.5 deg C warming due to the presence of urban areas across Singapore Island considering area-weighted distribution of LCZs and all-weather daily averages. This urban-induced warming is therefore of similar magnitude to that caused by anthropogenic global warming."(


The UHI study was picked up by The Straits Times newspaper: Heat and the city: High-rise areas get almost twice as hot as low-rise residential areas (

March 2023

Finally available on the WMO webpages:

Guidance on Measuring, Modelling and Monitoring the Canopy Layer Urban Heat Island (CL‑UHI) (


The guidance provides an overview of and recommendations for measuring, modelling and monitoring the canopy layer urban heat island (CL-UHI), which is based on temperature information at about 1.5 m above ground. It was put together by Heinke Schlünzen (Meteorological Institute, Universität Hamburg) and Sue Grimmond (Meteorology, University of Reading) as coordinating lead authors, with lead authors Alberto Martilli (CIEMAT, Spain), Valéry Masson (Météo France), Shiguang Miao (IUM CMA, China), Chao Ren (The University of Hong Kong), Matthias Roth (National University of Singapore), Iain D. Stewart (Global Cities Institute, Canada) and many contributing authors.

Link to web launch of the Guidance to Measuring, Modelling and Monitoring the Canopy Layer Urban Heat Island (CL-UHI):

wmo no-1292.jpg

May 2022

Prof Roth gave an invited presentation on ‘Climate change in cities' at the IAMES Science Forum, organised by The International Association of Meteorological Education (IAMES) and Sciences and Nanjing University of Information Science and Technology (NUIST):

Februrary 2021

The Global Heat Health Information Network (GHHIN) organised a Masterclass on 'Understanding, Modeling, and Mitigating Urban Heat Islands’ for participants to learn about the Urban Heat Island effect – what causes it, how we map and model it, and what we can do about it. 

Part 1 focused on 'Understanding Urban Heat: Urban Climate Science Background’ with Prof Roth presenting Lecture 2 'Essential elements of urban climatology for understanding the urban heat island effect'. The presentation is available here:

All four presentations can be viewed here:

January 2020

We had the pleasure to host Prof Sue Grimmond (Department of Meteorology, University of Reading) for a few weeks. During Sue’s visit as an IMMF fellow sponsored by FASS, we had early discussions about a potential urban heat island measurement guide, which eventually became a more comprehensive project and resulted in the publication of WMO document No. 1292: Guidance on Measuring, Modelling and Monitoring the Canopy Layer Urban Heat Island (CL‑UHI) (

September 2019

Lab lunch_edited.webp

Full contingent at the last lab lunch at the wonderful Riders Cafe (left to right): Manon, Matthias, Winston, Suli, Beatriz, Andrés and Minghong.

October 2019

Congratulations to Heng Suli who was recently conferred the Master of Social Science degree for her thesis “Using thermal walks to examine pedestrian’s thermal (dis)comfort when transiting across indoor, semi-outdoor and outdoor thermal environments in Singapore’s equatorial climate”. We wish her all the best in her future.

July 2019

Our trusted colleague, lab PI and supervisor Winston Chow is moving “downtown" to assume a new position as Associate Professor of Humanities at the Singapore Management University (SMU): (

May 2019

Prof Roth gave an invited presentation entitled ‘Losing our cool: cities and climate change' at the 1st International Workshop on Climate Change, Air pollution, and Public Health (CAPH) which was held at CUHK in Hong Kong, 30-31 May 2019.

March 2019

  • Su Li and Winston published a new analysis of an existing OTC dataset from the Singapore Botanic Gardens, calibrating OTC thresholds for physiological equivalent temperatures (PET) by analysing PET against thermal perception survey responses from the park visitors: 

  • Heng SL and Chow WTL, 2019. How ‘hot’ is too hot? Evaluating acceptable outdoor thermal comfort ranges in an equatorial urban park. International Journal of Biometeorology, 63:801–816 (

May 2018

  • A Singapore local climate zone (LCZ) map has been generated by Matthias Demuzere in collaboration with the Urban Climate Lab. It was recently published as part of a larger study on an image-based methodology to calculate urban canopy parameters at fine spatial scales from high resolution ground level imagery.​

  • Middle A, Lukasczyk J, Maciejewski R, Demuzere M and Roth M, 2018. Sky View Factor footprints for urban climate modeling. Urban Climate, 25, 120-134 (

Singapore LCZ map.png

February 2018

  • Congratulations to Marvin Seow who just published his honours thesis research. Marvin is now a graduate student with the Department of Earth and Planetary Science at The University of Tokyo ( : Seow MXC and Roth M, 2018. Influence of climate oscillations on urban and rural temperature variability in the Kanto region of Japan. Climate Research, 75, 65-80 (

MEI index_edited.png

October 2017

  • Minghong's second study site is up, just before the end of the month. It is hoped that this location will provide useful baseline or background data given its location in a relatively undeveloped area of Singapore, thought to be not much affected by urban development and anthropogenic actvity (though this is becoming increasingly more difficult to find). The picture on the right picture shows an attentive crew      watching over Minghong as he connects sensors to the data logger.

  • Sok Huang Tan's paper just got published! Her Masters thesis research on personal exposure to particles using different modes of transport in Singapore (bus, taxi, MRT and walking) was co-supervised by Matthias Roth and Erik Velasco (SMART-CENSAM):

rual station.jpg

July 2017

  • If you used the QR code from our signs at this contraption, and you're wondering what it is, click here or on the images for information... 

  • A number of modeling papers have been recently accepted/published using observational data from the energy flux tower (Roth et al. 2017): All three studies below use an 11-month long gap-filled time series of energy balance fluxes and meteorological data developed by Surj Harshan in his PhD work, and evaluate a range of urban land surface schemes:


May 2017

  • Prof Roth gave an invited presentation at the Urban Meteorology and Climate Conference held in Hong Kong from 25-26 May, 2017, which was jointly organised by the Asian Network on Climate Science and Technology, the City University of Hong Kong and the Hong Kong University of Science and Technology.

  • Just published: Roth M and Lim V, 2017. Evaluation of canopy-layer air and mean radiant temperature simulations by a microclimate model over a tropical residential neighbourhood. Building and Environment, 112, 177-189 (

  • The lab has a new postdoc - Dr. Manon Kohler! She will be working with Profs Roth and Chow on the Cooling Singapore project that the Urban Climate lab are involved in.

  • Prof Chow was awarded the 2016/2017 Award for Promising Researcher by the Faculty of Arts and Social Sciences. He received the award from the NUS Vice-Provost (Graduate Education) Prof Brenda Yeoh during the FASS STARS awards dinner held at the end of this academic year. The Faculty also interviewed Prof Chow about his award.

  • Prof Chow was also invited by the Intergovernmental Panel on Climate Change to contribute to the scoping of their Sixth Assessement Report, which will be published in 2021. The week-long meeting was held in Addis Ababa, Ethiopia, from May 1-5, 2017, and the outline should be made public after governmental review in September 2017.

November 2016

  • Prof Roth has been invited to give two lectures at:
    - The 5th Asia-Pacific International Conference organised by the Korea Legislation Research Institute in Seoul, Korea, 24-25 November 2016: "Building a Sustainable City - Singapore’s Approach to Climate Change"
    - 6th International Conference on Sustainable Energy and Environment in Bangkok, Thailand 28-30 November 2016:  "Urban Climate & Urban Air Pollution "Urban Climate Research and its Application to Real-World Problems"

  • Dr. Simón-Moral's latest paper (Effects of Unstable Thermal Stratification on Vertical Fluxes of Heat and Momentum in Urban Areas") was published in Boundary-Layer Meteorology -- it's available here!  

October 2016

  • Prof Chow will be giving a lunchtime seminar at the Lee Kuan Yew School of Public Policy titled "Urban Resilience Towards Extreme Weather Events: A Current Southeast Asian Perspective" on 31 October, Monday, 12:15 pm at the NUS Bukit Timah Campus. More information and registration details can be found here - free lunch if you register before Wednesday 26th October! 

​September 2016

  • Postdoctoral Researcher position open in our lab - deadline for application 30 October 2016. More information here! 

  • Roth et al (2017), "Multi-year energy balance and carbon dioxide fluxes over a residential neighbourhood in a tropical city" was just published in the International Journal of Climatology.

  • Gober et al. (2016) "Urban adaptation to mega-drought: Anticipatory water modeling, policy, and planning for the urban Southwest" has been published in the November issue of Sustainable Cities and Society.

  • We welcome Ms. Natsumi Kawano, a Ph.D. Student who is here on a visiting fellowship. She is a student from Professor Manabu Kanda's prestigious urban climate lab from Tokyo Institute of Technology!  

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